Characterization of keratinocyte differentiation induced by ascorbic acid: protein kinase C involvement and vitamin C homeostasis.

PubMed

Savini, Isabella; Catani, Maria Valeria; Rossi, Antonello; Duranti, Guglielmo; Melino, Gerry; Avigliano, Luciana

2002-02-01

Epidermal keratinocytes undergo differentiation in response to several stimuli to form the cornified envelope, a structure that contributes to the barrier function of skin. Although differentiation has been extensively analyzed, the precise role of vitamin C during this process is still not defined. Ascorbic acid, besides acting as a radical scavenger, has been shown to promote mesenchymal differentiation. In this study, we found that keratinocytes grown in ascorbate-supplemented medium developed a differentiated phenotype, as demonstrated by enhanced expression of marker genes and increase in cornified envelope content. The pro-differentiating effects of ascorbate were mediated by the protein-kinase-C-dependent induction of activating protein 1 DNA binding activity; indeed, down-modulation of protein kinase C activity abolished differentiation triggered by ascorbic acid. Although vitamin C appeared to regulate the same signaling pathway modulated by calcium, a classical in vitro inducer of epidermal differentiation, nonetheless terminally differentiated keratinocytes exhibited different ascorbate homeostasis and cellular antioxidant status. Indeed, we found that, unlike calcium, differentiation promoted by ascorbate was accompanied by (i) an enhanced ascorbate transport, due to overexpression of specific transporters, (ii) a great efficiency of dehydroascorbate uptake, and (iii) an increase in glutathione content with respect to proliferating cells. Ascorbic acid may be useful to promote epidermal differentiation, avoiding depletion of hydrophilic antioxidant stores.

Plant resistance mechanisms to air pollutants: rhythms in ascorbic acid production during growth under ozone stress

DOE Office of Scientific and Technical Information (OSTI.GOV)

Lee, E.H.

1991-01-01

Relationships between ozone (O3) tolerance and leaf ascorbic acid concentrations in O3-susceptible (O3-S) 'Hark' and O3-resistant (O3-R) 'Hood' soybean, Glycine max (L.) Merr., cultivars were examined with high-performance liquid chromatography (HPLC). Leaf samples were analyzed at 4 intervals during a 24 h period. Soybean cultivars grown in the greenhouse with charcoal filtered (CF) and nonfiltered (NF) air showed daily oscillations in ascorbic acid production. Highest ascorbic acid levels in leaves during light coincided with highest concentrations of photochemical oxidants in the atmosphere at 2:00 p.m. The resistant genotype produced more ascorbic acid in its trifoliate leaves than did the correspondingmore » susceptible genotype. Under CF air (an O3-reduced environment) O3-S and O3-R cultivars showed rhythms in ascorbic acid production. In NF air (an O3 stress environment) the O3-R cultivar alone showed rhythms in ascorbic acid production. Results indicated that superior O3 tolerance in the Hood soybean cultivar (compared with Hark) was associated with a greater increase in endogenous levels of ascorbic acid. Ascorbic acid may scavenge free radicals and thereby protect cells from injury by O3 or other oxyradical products. Plants defend themselves against photochemical oxidant stress, such as O3, by several mechanisms. Experimental evidence indicates that antioxidant defense systems existing in plant tissues may function to protect cellular components from deleterious effects of photochemical oxidants through endogenous and exogenous controls.« less

Assessment of antioxidant capacities and phenolic contents of nigerian cultivars of onions (Allium cepa L) and garlic (Allium sativum L).

PubMed

Onyeoziri, Ukoha Pius; Romanus, Ekere Nwachukwu; Onyekachukwu, Uzodinma Irene

2016-07-01

This report assessed and compared the antioxidant potentials, quantities of ascorbic acid and phenolic compounds in methanolic extract of varieties of onions and garlic cultivars in Nigeria. The pH and total acidity of the extracts were equally determined. Antioxidancy of the cultivars were analysed using the in vitro assay techniques with 2,2-diphenyl-1-picryl Hydrazyl (DPPH) free radical scavenging and ferric reducing capacity. Ascorbic acid phenolic content were determined by volumetric and Folin-Ciocalteu's method respectively. The pH and total acidity were respectively 5.65 and 0.150mmol/L (red onion), 5.69 and 0.123mmol/L (white onion) and 6.94 and 0.105mmol/L (garlic). Red onion had the highest value of total phenols, ascorbic acid and free radical scavenging activity of 14.25±0.35mg GAE/ml, 229.098mg/100g, 66.44% respectively. In DPPH assay, red and white onion showed higher tendency to inhibit auto-oxidation when compared to garlic. The ferric reducing ability was greatest in garlic and least in white onions. These data indicate that with respect to antioxidant activity, red onion variety has highest health promoting potential among others.

Hydroxyl radical scavenging assay of phenolics and flavonoids with a modified cupric reducing antioxidant capacity (CUPRAC) method using catalase for hydrogen peroxide degradation.

PubMed

Ozyürek, Mustafa; Bektaşoğlu, Burcu; Güçlü, Kubilay; Apak, Reşat

2008-06-02

Hydroxyl radicals (OH) generated in the human body may play an important role in tissue injury at sites of inflammation in oxidative stress-originated diseases. As a more convenient, efficient, and less costly alternative to HPLC/electrochemical detection techniques and to the nonspecific, low-yield deoxyribose (TBARS) test, we used a salicylate probe for detecting OH generated by the reaction of iron(II)-EDTA complex with H(2)O(2). The produced hydroxyl radicals attack both the salicylate probe and the hydroxyl radical scavengers that are incubated in solution for 10 min. Added radical scavengers compete with salicylate for the OH produced, and diminish chromophore formation from Cu(II)-neocuproine. At the end of the incubation period, the reaction was stopped by adding catalase. With the aid of this reaction, a kinetic approach was adopted to assess the hydroxyl radical scavenging properties of polyphenolics, flavonoids and other compounds (e.g., ascorbic acid, glucose, mannitol). A second-order rate constant for the reaction of the scavenger with OH could be deduced from the inhibition of colour formation due to the salicylate probe. In addition to phenolics and flavonoids, five kinds of herbs were evaluated for their OH scavenging activity using the developed method. The modified CUPRAC (cupric ion reducing antioxidant capacity) assay proved to be efficient for ascorbic acid, gallic acid and chlorogenic acid, for which the deoxyribose assay test is basically nonresponsive. An important contribution of this developed assay is the inhibition of the Fenton reaction with catalase degradation of hydrogen peroxide so that the remaining H(2)O(2) would neither give a CUPRAC absorbance nor involve in redox cycling of phenolic antioxidants, enabling the rapid assay of polyphenolics.

Exploration of pro-oxidant and antioxidant activities of the flavonoid myricetin.

PubMed

Chobot, Vladimir; Hadacek, Franz

2011-01-01

Flavonoids are ubiquitous phenolic plant metabolites. Many of them are well known for their pro- and antioxidant properties. Myricetin has been reported to be either a potent antioxidant or a pro-oxidant depending on the conditions. The reaction conditions for the pro- and antioxidant activities were therefore investigated using variations of the deoxyribose degradation assay systems. The deoxyribose degradation assay systems were conducted as follows; H(2)O(2)/Fe(III)/ascorbic acid, H(2)O(2)/Fe(III), Fe(III)/ascorbic acid, and Fe(III). Each system was carried out in two variants, FeCl(3) (iron ions added as FeCl(3)) and FeEDTA (iron added in complex with ethylenediaminetetraacetic acid). When ascorbic acid was present, myricetin showed antioxidant properties, especially when it occurred in complex with iron. In ascorbic acid-free systems, pro-oxidant activities prevailed, which where enhanced if iron was in complex with EDTA. Myricetin's antioxidant activity depends on both the reactive oxygen species (ROS) scavenging and iron ions chelation properties. The pro-oxidative properties are caused by reduction of molecular oxygen to ROS and iron(III) to iron(II). Myricetin is able to substitute for ascorbic acid albeit less efficiently.

Betalain, Acid Ascorbic, Phenolic Contents and Antioxidant Properties of Purple, Red, Yellow and White Cactus Pears

PubMed Central

Sumaya-Martínez, María Teresa; Cruz-Jaime, Sandra; Madrigal-Santillán, Eduardo; García-Paredes, Juan Diego; Cariño-Cortés, Raquel; Cruz-Cansino, Nelly; Valadez-Vega, Carmen; Martinez-Cardenas, Leonardo; Alanís-García, Ernesto

2011-01-01

Commercialization of cactus pears based on their antioxidant properties can generate competitive advantages, and these can turn into business opportunities and the development of new products and a high-value ingredient for the food industry. This work evaluated the antioxidant activities (1,1-diphenyl-2-picrylhydrazyl radical-scavenging, protection against oxidation of a β-carotene-linoleic acid emulsion, and iron (II) chelation), the content of total phenolic compounds, ascorbic acid, betacyanin, betaxanthin and the stability of betacyanin pigments in presence of Cu (II)-dependent hydroxyl radicals (OH•), in 18 cultivars of purple, red, yellow and white cactus pear from six Mexican states. Our results indicated that the antiradical activities from yellow and white cactus pear cultivars were not significantly different (p < 0.05) and were lower than the average antiradical activities in red and purple cultivars. The red cactus pear from the state of Zacatecas showed the highest antioxidant activity. The free radical scavenging activity for red cactus pears was significantly correlated (p < 0.05) to the concentration of total phenolic compounds (R2 = 0.90) and ascorbic acid (R2 = 0.86). All 18 cultivars of cactus pears studied showed significant chelating activity of ferrous ions. The red and purple cactus pears showed a great stability when exposed to OH•. PMID:22072899

Antioxidant activity and total phenolic content of ethanolic extract of Caesalpinia bonducella seeds.

PubMed

Shukla, Shruti; Mehta, Archana; John, Jinu; Singh, Siddharth; Mehta, Pradeep; Vyas, Suresh Prasad

2009-08-01

The aim of this study was to assess the in vitro potential of ethanolic extract of Caesalpinia bonducella seeds as a natural antioxidant. The DPPH activity of the extract (20, 40, 50, 100 and 200 microg/ml) was increased in a dose dependent manner, which was found in the range of 38.93-74.77% as compared to ascorbic acid (64.26-82.58%). The IC(50) values of ethanolic extract and ascorbic acid in DPPH radical scavenging assay were obtained to be 74.73 and 26.68 microg/ml, respectively. The ethanolic extract was also found to scavenge the superoxide generated by EDTA/NBT system. Measurement of total phenolic content of the ethanolic extract of C. bonducella was achieved using Folin-Ciocalteau reagent containing 62.50mg/g of phenolic content, which was found significantly higher when compared to reference standard gallic acid. The ethanolic extract also inhibited the hydroxyl radical, nitric oxide, superoxide anions with IC(50) values of 109.85, 102.65 and 89.84 microg/ml, respectively. However, the IC(50) values for the standard ascorbic acid were noted to be 70.79, 65.98 and 36.68 microg/ml respectively. The results obtained in this study clearly indicate that C. bonducella has a significant potential to use as a natural antioxidant agent.

Ascorbic acid reduces noise-induced nitric oxide production in the guinea pig ear.

PubMed

Heinrich, Ulf-Rüdiger; Fischer, Ilka; Brieger, Jürgen; Rümelin, Andreas; Schmidtmann, Irene; Li, Huige; Mann, Wolf J; Helling, Kai

2008-05-01

Noise-induced hearing loss can be caused, among other causes, by increased nitric oxide (NO) production in the inner ear leading to nitroactive stress and cell destruction. Some studies in the literature suggest that the degree of hearing loss (HL) could be reduced in an animal model through ascorbic acid supplementation. To identify the effect of ascorbic acid on tissue-dependent NO content in the inner ear of the guinea pig, we determined the local NO production in the organ of Corti and the lateral wall separately 6 hours after noise exposure. Prospective animal study in guinea pigs. Over a period of 7 days, male guinea pigs were supplied with minimum (25 mg/kg body weight/day) and maximum (525 mg/kg body weight/day) ascorbic acid doses, and afterwards exposed to noise (90 dB sound pressure level for 1 hour). The acoustic-evoked potentials were recorded before and after noise exposure. The organ of Corti and the lateral wall were incubated differently for 6 hours in culture medium, and the degree of NO production was determined by chemiluminescence. Ascorbic acid treatment reduced the hearing threshold shift after noise exposure depending on concentration. When the maximum ascorbic acid dose was substituted, NO production was significantly reduced in the lateral wall after noise exposure and slightly reduced in the organ of Corti. Oral supplementation of the natural radical scavenger ascorbic acid reduces the NO-production rate in the inner ear in noisy conditions. This finding supports the concept of inner ear protection by ascorbic acid supplementation.

Change in chemical constituents and free radical-scavenging activity during Pear (Pyrus pyrifolia) cultivar fruit development.

PubMed

Cho, Jeong-Yong; Lee, Sang-Hyun; Kim, Eun Hee; Yun, Hae Rim; Jeong, Hang Yeon; Lee, Yu Geon; Kim, Wol-Soo; Moon, Jae-Hak

2015-01-01

Changes in chemical constituent contents and DPPH radical-scavenging activity in fruits of pear (Pyrus pyrifolia) cultivars during the development were investigated. The fruits of seven cultivars (cv. Niitaka, Chuhwangbae, Wonhwang, Hwangkeumbae, Hwasan, Manpungbae, and Imamuraaki) were collected at 15-day intervals after day 20 of florescence. Vitamins (ascorbic acid and α-tocopherol), arbutin, chlorogenic acid, malaxinic acid, total caffeic acid, total flavonoids, and total phenolics were the highest in immature pear fruit on day 20 after florescence among samples at different growth stages. All of these compounds decreased gradually in the fruit during the development. Immature pear fruit on day 35 or 50 after florescence exhibited higher free radical-scavenging activity than that at other times, although activities were slightly different among cultivars. The chemical constituent contents and free radical-scavenging activity were largely different among immature fruits of the pear cultivars, but small differences were observed when they matured.

Chemical repair of base lesions, AP-sites, and strand breaks on plasmid DNA in dilute aqueous solution by ascorbic acid

DOE Office of Scientific and Technical Information (OSTI.GOV)

Hata, Kuniki; Advanced Science Research Center, Japan Atomic Energy Agency, 2-4 Shirakatashirane, Tokai-mura, Naka-gun, Ibaraki 319-1195; Urushibara, Ayumi

Highlights: •We report a novel mechanism of radiation protection of DNA by chemical activity of ascorbic acid. •The “chemical repair” of DNA damage was revealed using biochemical assay and chemical kinetics analysis. •We found that ascorbic acid significantly repairs precursors of nucleobase lesions and abasic sites. •However, ascorbic acid seldom repairs precursors of DNA-strand breaks. -- Abstract: We quantified the damage yields produced in plasmid DNA by γ-irradiation in the presence of low concentrations (10–100 μM) of ascorbic acid, which is a major antioxidant in living systems, to clarify whether it chemically repairs radiation damage in DNA. The yield ofmore » DNA single strand breaks induced by irradiation was analyzed with agarose gel electrophoresis as conformational changes in closed circular plasmids. Base lesions and abasic sites were also observed as additional conformational changes by treating irradiated samples with glycosylase proteins. By comparing the suppression efficiencies to the induction of each DNA lesion, in addition to scavenging of the OH radicals derived from water radiolysis, it was found that ascorbic acid promotes the chemical repair of precursors of AP-sites and base lesions more effectively than those of single strand breaks. We estimated the efficiency of the chemical repair of each lesion using a kinetic model. Approximately 50–60% of base lesions and AP-sites were repaired by 10 μM ascorbic acid, although strand breaks were largely unrepaired by ascorbic acid at low concentrations. The methods in this study will provide a route to understanding the mechanistic aspects of antioxidant activity in living systems.« less

Antioxidant potential of n-butanol fraction from extract of Jasminum mesnyi Hance leaves.

PubMed

Borar, Sakshi; Punia, Priyanka; Kalia, A N

2011-01-01

Methanolic extract of Jasminum mesnyi Hance leaves having antidiabetic activity was subjected to fractionation to obtain antioxidant and antihyperglycemic rich fraction. Different concentrations of ethyl acetate and n-butanol fractions were subjected to antioxidant assay by DPPH method, nitric oxide scavenging activity and reducing power assay. The fractions showed dose dependent free radical scavenging property in all the models. IC50 values for ethyl acetate and n-butanol fractions were 153.45 +/- 6.65 and 6.22 +/- 0.25 microg/ml, respectively, as compared to L-ascorbic acid and rutin (as standards; IC50 values 6.54 +/- 0.24 and 5.43 +/- 0.21 microg/ml, respectively) in DPPH model. In nitric oxide scavenging activity, IC50 values were 141.54 +/- 9.95 microg/ml, 35.12 +/- 1.58 microg/ml, 21.06 +/- 0.95 microg/ml and 29.93 +/- 0.32 microg/ml for ethyl acetate, n-butanol fractions, L-ascorbic acid and rutin, respectively. n-Butanol fraction showed a good reducing potential and better free radical scavenging activity as compared to ethyl acetate fraction. Potent antioxidant n-butanol fraction showed better oral glucose tolerance test (antihyperglycemic) at par with metformin (standard drug), n-Butanol fraction contained secoiridoid glycosides which might be responsible for both antioxidant and antihyperglycemic activity.

Characterization of the antioxidant properties of hydrophilic and lipophilic extracts of Jute (Corchorus olitorius) leaf.

PubMed

Oboh, G; Raddatz, H; Henle, T

2009-01-01

Corchorus olitorius (jute) is a native plant of tropical Africa and Asia, and has since spread to Australia, South America and some parts of Europe. Its leafy vegetable is popularly used in soup preparation and folk medicine for the treatment of fever, chronic cystitis, cold and tumours. A comparative study of the antioxidant properties of hydrophilic extract (HE) and lipophilic extract (LE) constituents of the leafy vegetable has been assessed. HE and LE of the leaf were prepared using water and hexane, respectively and their antioxidant properties were determined. HE had a significantly higher (P<0.05) 1,1-diphenyl-2-picrylhydrazyl radical-scavenging ability (aqueous, 9.6-84.4%; hexane, 2.0-20.4%), reducing power (aqueous, 0.67 mmol ascorbic acid equivalent/g; hexane, 0.49 mmol ascorbic acid equivalent/g) and trolox equivalent antioxidant capacity (aqueous, 2.3 mmol/g; hexane, 1.1 mmol/g) than LE; conversely, LE had a significantly higher (P<0.05) OH. scavenging activity (44.5-46.2%) than HE (11.6-32.3%), while there was no significant difference (P>0.05) in their Fe(II) chelating ability (HE, 57.7-66.7%; LE, 56.4-61.1%). The higher 1,1-diphenyl-2-picrylhydrazyl radical-scavenging ability, reducing power and trolox equivalent antioxidant capacity of the hydrophilic extract may be due to its significantly higher (P<0.05) total phenol (630.8 mg/100 g), total flavonoid (227.8 mg/100 g) and non-flavonoid polyphenols (403.0 mg/100 g), and its high ascorbic acid content (32.6 mg/100 g). While the higher OH. scavenging ability of LE may be due to its high total carotenoid content (42.5 mg/100 g). Therefore, the additive/synergistic antioxidant activities of the hydrophilic and lipophilic constituents may contribute to the medicinal properties of C. olitorius leaf.

Novel roles of ascorbate in plants: induction of cytosolic Ca2+ signals and efflux from cells via anion channels.

PubMed

Makavitskaya, M; Svistunenko, D; Navaselsky, I; Hryvusevich, P; Mackievic, V; Rabadanova, C; Tyutereva, E; Samokhina, V; Straltsova, D; Sokolik, A; Voitsekhovskaja, O; Demidchik, V

2018-02-17

Ascorbate is not often considered as a signalling molecule in plants. This study demonstrates that, in Arabidopsis roots, exogenous L-ascorbic acid triggers a transient increase of the cytosolic free calcium activity ([Ca2+]cyt.) that is central to plant signalling. Exogenous copper and iron stimulates the ascorbate-induced [Ca2+]cyt. elevation while cation channel blockers, free radical scavengers, low extracellular [Ca2+], transition metal chelators and removal of the cell wall inhibit this reaction. These data show that apoplastic redox-active transition metals are involved in the ascorbate-induced [Ca2+]cyt. elevation. Exogenous ascorbate also induces a moderate increase in programmed cell death symptoms in intact roots, but it does not activate Ca2+ influx currents in patch-clamped root protoplasts. Intriguingly, the replacement of gluconate with ascorbate in the patch-clamp pipette reveales a large ascorbate efflux current, which shows sensitivity to the anion channel blocker, anthracene-9-carboxylic acid (A9C), indicative of the ascorbate release via anion channels. EPR spectroscopy measurements demonstrates that salinity (NaCl) triggers the accumulation of root apoplastic ascorbyl radicals in A9C-dependent manner, confirming that L-ascorbate leaks through anion channels under depolarisation. This mechanism may underlie ascorbate release, signalling phenomena, apoplastic redox reactions, iron acquisition and control the ionic and electrical equilibrium (together K+ efflux via GORK channels).

Changes in free-radical scavenging ability of kombucha tea during fermentation.

PubMed

Jayabalan, R; Subathradevi, P; Marimuthu, S; Sathishkumar, M; Swaminathan, K

2008-07-01

Kombucha tea is a fermented tea beverage produced by fermenting sugared black tea with tea fungus (kombucha). Free-radical scavenging abilities of kombucha tea prepared from green tea (GTK), black tea (BTK) and tea waste material (TWK) along with pH, phenolic compounds and reducing power were investigated during fermentation period. Phenolic compounds, scavenging activity on DPPH radical, superoxide radical (xanthine-xanthine oxidase system) and inhibitory activity against hydroxyl radical mediated linoleic acid oxidation (ammonium thiocyanate assay) were increased during fermentation period, whereas pH, reducing power, hydroxyl radical scavenging ability (ascorbic acid-iron EDTA) and anti-lipid peroxidation ability (thiobarbituric assay) were decreased. From the present study, it is obvious that there might be some chances of structural modification of components in tea due to enzymes liberated by bacteria and yeast during kombucha fermentation which results in better scavenging performance on nitrogen and superoxide radicals, and poor scavenging performance on hydroxyl radicals. Copyright © 2007 Elsevier Ltd. All rights reserved.

Protective role of ascorbic acid in the decontamination of cow milk casein by gamma-irradiation.

PubMed

Kouass Sahbani, Saloua; Klarskov, Klaus; Aloui, Amine; Kouass, Salah; Landoulsi, Ahmed

2013-06-01

The aim of this work was to investigate the protective role of ascorbic acid on irradiation-induced modification of casein. Casein stock solutions were irradiated with increasing doses 2-10 kGy using (60)Co Gamma rays at a dose rate D• = 136.73 Gy/min at room temperature. The total viable microorganism content of cow milk casein was evaluated by Plate Count Agar (PCA) incubation for 48 h at 37°C. Sodium dodecylsulfate gel electrophoresis (SDS-PAGE) and Matrix-Assisted Laser Desorption-Ionization Time-of-Flight mass spectrometry (MALDI-TOF-MS) analysis were used to evaluate the effect of gamma irradiation on casein integrity. Gamma irradiation reduced the bacterial contamination of casein solutions at a lower irradiation dose when performed in the presence of ascorbic acid. The irradiation treatment of casein in the absence of ascorbic acid with a dose of 4 kGy could reduce 99% of the original amount of bacterial colonies. However, in the presence of ascorbic acid the irradiation treatment of casein with a dose lower than 2 kGy could reduce 99% of the original amount of bacterial colonies which suggested that the irradiation dose lower than 2 kGy achieved almost the entire decontamination result. SDS-PAGE and MALDI-TOF-MS analysis showed that ascorbic acid protected cow milk casein from degradation and subsequent aggregation probably by scavenging oxygen and protein radicals produced by the irradiation. It is demonstrated that the combination of gamma irradiation and ascorbic acid produce additive effects, providing acceptable hygienic quality of cow milk casein and protects caseins against Reactive Oxygen Species (ROS) generated, during the irradiation process.

Change in the ascorbic acid, total phenol and antioxidant activity of sun-dried commonly consumed green leafy vegetables in Nigeria.

PubMed

Oboh, G; Akindahunsi, A A

2004-01-01

Sun-drying of green leafy vegetables is popularly practised in many homes in Nigeria, as a way of preserving green leafy vegetables for future use. This project sought to investigate the effect of this method of preservation of vegetables on the antioxidant phytoconstituent (Vitamin C and Total phenol) and activity (reducing property and free radical scavenging ability) of some commonly consumed green leafy vegetables in Nigeria namely Structium sparejanophora (Ewuro-odo), Amarantus cruentus (Atetedaye), Telfairia occidentalis (Ugu), Baselia allia (Amunu tutu), Solanum macrocarpon (Igbagba), Corchorus olitorius (Ewedu), Vernonia anygdalina (Ewuro) and Occimum graticimum (Efinrin). The edible portions of the green leafy vegetables were sun-dried for seven days before determining the Vitamin C and total phenol content, as well as the reducing property and free radical scavenging ability. The result of the study revealed that sun-drying of green leafy vegetables cause a significant (P < 0.05) decrease in the Vitamin C content (16.67-64.68% loss). Conversely it leads to a significant increase in the total phenol content (6.45-223.08% gain), reducing property (16.00-362.50% gain) and free radical scavenging ability (126.00-5757.00% gain) of the green leafy vegetables. It could therefore be concluded that a significant decrease (P < 0.05) in Vitamin C content caused by sun- drying will not reduce the antioxidant activity of the green leafy vegetable, moreover, the phenol constituent of the green leafy vegetables contributes more to the antioxidant properties of vegetables than ascorbic acid, as its increase on sun-drying cause a significant (P < 0.05) increases in the antioxidant properties of the green leafy vegetables, irrespective of the decrease in the ascorbic acid content.

Ascorbic Acid-A Potential Oxidant Scavenger and Its Role in Plant Development and Abiotic Stress Tolerance

PubMed Central

Akram, Nudrat A.; Shafiq, Fahad; Ashraf, Muhammad

2017-01-01

Over-production of reactive oxygen species (ROS) in plants under stress conditions is a common phenomenon. Plants tend to counter this problem through their ability to synthesize ROS neutralizing substances including non-enzymatic and enzymatic antioxidants. In this context, ascorbic acid (AsA) is one of the universal non-enzymatic antioxidants having substantial potential of not only scavenging ROS, but also modulating a number of fundamental functions in plants both under stress and non-stress conditions. In the present review, the role of AsA, its biosynthesis, and cross-talk with different hormones have been discussed comprehensively. Furthermore, the possible involvement of AsA-hormone crosstalk in the regulation of several key physiological and biochemical processes like seed germination, photosynthesis, floral induction, fruit expansion, ROS regulation and senescence has also been described. A simplified and schematic AsA biosynthetic pathway has been drawn, which reflects key intermediates involved therein. This could pave the way for future research to elucidate the modulation of plant AsA biosynthesis and subsequent responses to environmental stresses. Apart from discussing the role of different ascorbate peroxidase isoforms, the comparative role of two key enzymes, ascorbate peroxidase (APX) and ascorbate oxidase (AO) involved in AsA metabolism in plant cell apoplast is also discussed particularly focusing on oxidative stress perception and amplification. Limited progress has been made so far in terms of developing transgenics which could over-produce AsA. The prospects of generation of transgenics overexpressing AsA related genes and exogenous application of AsA have been discussed at length in the review. PMID:28491070

Antioxidant properties of selected fruit cultivars grown in Sri Lanka.

PubMed

Silva, K D R R; Sirasa, M S F

2018-01-01

Extracts of twenty locally available Sri Lankan fruits were analysed for 2,2-diphenyl-1-picrylhydrazyl (DPPH) scavenging activity, ferrous reducing antioxidant power (FRAP), total phenolic content (TPC), total flavonoid content (TFC) and vitamin C content. The results showed that gooseberry (Phyllanthus emblica 'local') exhibited the highest DPPH scavenging activity (111.25mg ascorbic acid equivalent antioxidant capacity (AEAC)/g), FRAP (1022.05μmol FeSO 4 /g), TPC (915.7mg gallic acid equivalents (GAE)/100g), TFC (873.2mg catechin equivalents (CE)/100g) and vitamin C (136.8mg ascorbic acid equivalents (AAE)/100g), respectively. Sugar apple (Annona squamosa 'local') and star fruit (Averrhoa carambola 'Honey Sweet') obtained the second and third highest antioxidant activities in terms of rankings of FRAP, DPPH activities, TPC, TFC and vitamin C content. Strong correlation between vitamin C, TPC and TFC with FRAP and DPPH showed their contribution to antioxidant capacity. Among the selected fruits, underutilized fruit cultivar gooseberry showed the highest overall antioxidant potential. Copyright © 2016 Elsevier Ltd. All rights reserved.

Anti-inflammatory and antioxidant activities of ethanolic extract of aerial parts of Vernonia patula (Dryand.) Merr.

PubMed Central

Hira, Arpona; Dey, Shubhra Kanti; Howlader, Md. Sariful Islam; Ahmed, Arif; Hossain, Hemayet; Jahan, Ismet Ara

2013-01-01

Objective To investigate the inflammatory and antioxidant activities of ethanolic extract of aerial part of Vernonia patula (Dryand.) Merr (EAV). Methods The anti-inflammatory activity of EAV was studied using carrageenan and histamine-induced rat paw edema test at different doses (100, 200 and 400 mg/kg body weight). DPPH free radical scavenging, nitric oxide scavenging, reducing power and Fe2+ ion chelating ability were used for determining antioxidant activities. Results The EAV, at the dose of 400 mg/kg, showed a significant anti-inflammatory activity (P<0.01) both in the carrageenan and histamine-induced oedema test models in rats, showing 62.86% and 64.42% reduction in the paw volume comparable to that produced by the standard drug indomethacin (67.26% and 66.01%) at 5 h respectively. In DPPH free radical scavenging test, IC50 value for EAV was found fairly significant 36.59 µg/mL when compared to the IC50 value of the reference standards ascorbic acid 8.97 µg/mL. The IC50 values of the extract and ascorbic acid were 47.72 and 12.39 µg/mL, respectively in nitric oxide scavenging assay. The IC50 value of the EAV (33.59 µg/mL) as percentage of Fe2+ ion chelating ability was also found significant compared to that of EDTA (9.16 µg/mL). The maximum absorbance for reducing power assay was found to be 1.928 at 100 µg/mL when compared to 2.449 for standard ascorbic acid. The total phenolic content was 198.81 mg/g of gallic acid equivalent. Acute toxicity test showed that the plant might be safe for pharmacological uses up to a dose level of 3 200 mg/kg of body weight in rats. Conclusions Therefore, the obtained results suggest the acute anti-inflammatory and antioxidant activities of the EAV and thus provide the scientific basis for the traditional uses of this plant part as a remedy for inflammations. PMID:24075345

A study of extraction process and in vitro antioxidant activity of total phenols from Rhizoma Imperatae.

PubMed

Zhou, Xian-rong; Wang, Jian-hua; Jiang, Bo; Shang, Jin; Zhao, Chang-qiong

2013-01-01

The study investigated the extraction method of Rhizoma Imperatae and its antioxidant activity, and provided a basis for its rational development. The extraction method of Rhizoma Imperatae was determined using orthogonal design test and by total phenol content, its hydroxyl radical scavenging ability was measured by Fenton reaction, and potassium ferricyanide reduction method was used to determine its reducing power. The results showed that the optimum extraction process of Rhizoma Imperatae was a 50-fold volume of water, 30 °C, three times of extraction with 2 h each. Its IC50 for scavenging of hydroxyl radicals was 0.0948 mg/mL, while IC50 of ascorbic acid was 0.1096 mg/mL; in the ferricyanide considerable reduction method, the extract exhibited reducing power comparable to that of the ascorbic acid. The study concluded that Rhizoma Imperatae extract contains relatively large amount of polyphenols, and has a good anti-oxidation ability.

Antioxidant Defenses in Plants with Attention to Prunus and Citrus spp.

PubMed Central

Racchi, Milvia Luisa

2013-01-01

This short review briefly introduces the formation of reactive oxygen species (ROS) as by-products of oxidation/reduction (redox) reactions, and the ways in which the antioxidant defense machinery is involved directly or indirectly in ROS scavenging. Major antioxidants, both enzymatic and non enzymatic, that protect higher plant cells from oxidative stress damage are described. Biochemical and molecular features of the antioxidant enzymes superoxide dismutase (SOD), catalase (CAT), and ascorbate peroxidase (APX) are discussed because they play crucial roles in scavenging ROS in the different cell compartments and in response to stress conditions. Among the non enzymatic defenses, particular attention is paid to ascorbic acid, glutathione, flavonoids, carotenoids, and tocopherols. The operation of ROS scavenging systems during the seasonal cycle and specific developmental events, such as fruit ripening and senescence, are discussed in relation to the intense ROS formation during these processes that impact fruit quality. Particular attention is paid to Prunus and Citrus species because of the nutritional and antioxidant properties contained in these commonly consumed fruits. PMID:26784469

Changes in antioxidant and biochemical activities in castor oil-coated Capsicum annuum L. during postharvest storage.

PubMed

Panigrahi, Jitendriya; Patel, Mansi; Patel, Niyati; Gheewala, Bhumi; Gantait, Saikat

2018-06-01

This study, for the first time, evaluates the efficiency of castor oil when used as an external coating on Capsicum annuum L., to increase postharvest storage-life at 4 ± 1 °C. The castor oil-coated fruits were successfully stored for 36 days, while the non-coated fruits could only sustain for 18 days. Throughout the storage period (at 9-day intervals), different antioxidants and biochemical assays (allied with storage) such as titratable acidity, ascorbic acid content, ferrous ion chelating activity, reducing power, DPPH scavenging activity, hydroxyl radical scavenging activity, total phenolic content, total sugar estimation, and enzymatic study of polyphenol oxidase and pectate lyase, were assessed. During storage, the castor oil-coated fruits showed a substantial decrease in titratable acidity, ascorbic acid content, total phenolic content, including antioxidant activities such as reducing power and DPPH activity; however, an increase in ferrous ion chelating activity, total soluble sugar content, polyphenol oxidase activity and initial pectate lyase activity was observed, in contrast to that of the non-coated fruits. The application of castor oil proved to be effective in delaying the ripening process of fruits during storage.

Combined Effects of Lanthanum (III) and Acid Rain on Antioxidant Enzyme System in Soybean Roots.

PubMed

Zhang, Xuanbo; Du, Yuping; Wang, Lihong; Zhou, Qing; Huang, Xiaohua; Sun, Zhaoguo

2015-01-01

Rare earth element pollution (REEs) and acid rain (AR) pollution simultaneously occur in many regions, which resulted in a new environmental issue, the combined pollution of REEs and AR. The effects of the combined pollution on the antioxidant enzyme system of plant roots have not been reported. Here, the combined effects of lanthanum ion (La3+), one type of REE, and AR on the antioxidant enzyme system of soybean roots were investigated. In the combined treatment of La3+ (0.08 mM) and AR, the cell membrane permeability and the peroxidation of cell membrane lipid of soybean roots increased, and the superoxide dismutase, catalase, peroxidase and reduced ascorbic acid served as scavengers of reactive oxygen species. In other combined treatments of La3+ (0.40 mM, 1.20 mM) and AR, the membrane permeability, malonyldialdehyde content, superoxide dismutase activity, peroxidase activity and reduced ascorbic acid content increased, while the catalase activity decreased. The increased superoxide dismutase activity, peroxidase activity and reduced ascorbic acid content were inadequate to scavenge the excess hydrogen peroxide and superoxide, leading to the damage of the cell membrane, which was aggravated with the increase in the concentration of La3+ and the level of AR. The deleterious effects of the combined treatment of La3+ and AR were stronger than those of the single treatment of La3+ or AR. Moreover, the activity of antioxidant enzyme system in the combined treatment group was affected directly and indirectly by mineral element content in soybean plants.

Combined Effects of Lanthanum (III) and Acid Rain on Antioxidant Enzyme System in Soybean Roots

PubMed Central

Zhang, Xuanbo; Du, Yuping; Wang, Lihong; Zhou, Qing; Huang, Xiaohua; Sun, Zhaoguo

2015-01-01

Rare earth element pollution (REEs) and acid rain (AR) pollution simultaneously occur in many regions, which resulted in a new environmental issue, the combined pollution of REEs and AR. The effects of the combined pollution on the antioxidant enzyme system of plant roots have not been reported. Here, the combined effects of lanthanum ion (La3+), one type of REE, and AR on the antioxidant enzyme system of soybean roots were investigated. In the combined treatment of La3+ (0.08 mM) and AR, the cell membrane permeability and the peroxidation of cell membrane lipid of soybean roots increased, and the superoxide dismutase, catalase, peroxidase and reduced ascorbic acid served as scavengers of reactive oxygen species. In other combined treatments of La3+ (0.40 mM, 1.20 mM) and AR, the membrane permeability, malonyldialdehyde content, superoxide dismutase activity, peroxidase activity and reduced ascorbic acid content increased, while the catalase activity decreased. The increased superoxide dismutase activity, peroxidase activity and reduced ascorbic acid content were inadequate to scavenge the excess hydrogen peroxide and superoxide, leading to the damage of the cell membrane, which was aggravated with the increase in the concentration of La3+ and the level of AR. The deleterious effects of the combined treatment of La3+ and AR were stronger than those of the single treatment of La3+ or AR. Moreover, the activity of antioxidant enzyme system in the combined treatment group was affected directly and indirectly by mineral element content in soybean plants. PMID:26230263

Chromium-induced membrane damage: protective role of ascorbic acid.

PubMed

Dey, S K; Nayak, P; Roy, S

2001-07-01

Importance of chromium as environmental toxicant is largely due to impact on the body to produce cellular toxicity. The impact of chromium and their supplementation with ascorbic acid was studied on plasma membrane of liver and kidney in male Wistar rats (80-100 g body weight). It has been observed that the intoxication with chromium (i.p.) at the dose of 0.8 mg/100 g body weight per day for a period of 28 days causes significant increase in the level of cholesterol and decrease in the level of phospholipid of both liver and kidney. The alkaline phosphatase, total ATPase and Na(+)-K(+)-ATPase activities were significantly decreased in both liver and kidney after chromium treatment, except total ATPase activity of kidney. It is suggested that chromium exposure at the present dose and duration induce for the alterations of structure and function of both liver and kidney plasma membrane. Ascorbic acid (i.p. at the dose of 0.5 mg/100 g body weight per day for period of 28 days) supplementation can reduce these structural changes in the plasma membrane of liver and kidney. But the functional changes can not be completely replenished by the ascorbic acid supplementation in response to chromium exposure. So it is also suggested that ascorbic acid (nutritional antioxidant) is useful free radical scavenger to restrain the chromium-induced membrane damage.

Lipid peroxidation inhibition and antiradical activities of some leaf fractions of Mangifera indica.

PubMed

Badmus, Jelili A; Adedosu, Temitope O; Fatoki, John O; Adegbite, Victor A; Adaramoye, Oluwatosin A; Odunola, Oyeronke A

2011-01-01

This study was undertaken to assess in vitro lipid peroxidation inhibitions and anti-radical activities of methanolic, chloroform, ethyl acetate and water fractions of Mangifera indica leaf. Inhibition of Fe(2+)-induced lipid peroxidation (LPO) in egg, brain, and liver homogenates, 1,1-diphenyl-2-picrylhydrazyl (DPPH) and hydroxyl (OH-) radical scavenging activities were evaluated. Total phenol was assessed in all fractions, and the reducing power of methanolic fraction was compared to gallic acid and ascorbic acid. The results showed that Fe2+ induced significant lipid peroxidation (LPO) in all the homogenates. Ethyl acetate fraction showed the highest percentage inhibition of LPO in both egg yolk (68.3%) and brain (66.3%), while the aqueous fraction exerted the highest inhibition in liver homogenate (89.1%) at a concentration of 10 microg/mL. These observed inhibitions of LPO by these fractions were higher than that of ascorbic acid used as a standard. The DPPH radical scavenging ability exhibited by ethyl acetate fraction was found to be the highest with IC50 value of 1.5 microg/mL. The ethyl acetate and methanolic fractions had the highest OH- radical scavenging ability with the same IC50 value of 5 microg/mL. The total phenol content of ethyl acetate fraction was the highest with 0.127 microg/mg gallic acid equivalent (GAE). The reductive potential of methanolic fraction showed a concentration-dependent increase. This study showed that inhibition of LPO and the DPPH and OH- radicals scavenging abilities of Mangifera indica leaf could be related to the presence of phenolic compounds. Therefore, the ethyl acetate fraction of the leaf may be a good source of natural antioxidative agent.

Evaluation of the antioxidant activity of root extract of pepper fruit (Dennetia tripetala), and it's potential for the inhibition of lipid peroxidation.

PubMed

Okolie, Ngozi Paulinus; Falodun, Abiodun; Davids, Oluseyi

2014-01-01

The antioxidant properties of ethanolic root extract of pepper fruit (Donnetia tripetala), and its effect on lipid peroxidation of some fresh beef tissues during frozen storage were investigated. The antioxidant parameters were assessed using standard methods, while malondialdehyde levels of different fresh beef tissue sections treated with the extract prior to freezing, were estimated in a colorimetric reaction with thiobarbituric acid. The H2O2-scavenging ability of the extract was similar to that of ascorbic acid, with a maximum scavenging power of 55.61 ±4.98%, and an IC50 value of 86µg/ml. The extract exhibited a concentration-dependent ferric ion-reducing power, although this was significantly lower relative to that of the ascorbic acid (p < 0.05). The total phenolic content was 212.5 ± 0.002 mg/g, while the nitric oxide-scavenging ability was 64.33 ± 0.2% after 150 min. The capacity of the extract to inhibit lipid peroxidation in frozen heart muscle slices was significantly higher than that of vitamin C (p < 0 .05), but comparable to vitamins C and E in frozen testes and kidney slices. These results suggest that the root extract of D. tripetala is rich in antioxidants which can be applied to meat preservation during refrigerated storage.

ASCORBIC ACID REDUCTION OF RESIDUAL ACTIVE CHLORINE IN POTABLE WATER PRIOR TO HALOCARBOXYLATE DETERMINATION

EPA Science Inventory

In studies on the formation of disinfection byproducts (DBPs), it is necessary to scavenge residual active (oxidizing) chlorine in order to fix the chlorination byproducts (such as haloethanoates) at a point in time. Thus, methods designed for compliance monitoring are not alway...

ASCORBIC ACID REDUCTION ON RESIDUAL ACTIVE CHLORINE IN POTABLE WATER PRIOR TO HALOCARBOXYLATE DETERMINATION

EPA Science Inventory

In studies on the formation of disinfection byproducts (DBPs), it is necessary to scavenge residual active (odxidizing) chlorine in order to fix the chlorination byproducts (such as haloethanoates) at a point in time . Such research projects often have distinct needs from requi...

Influence of cultivar and ripening time on bioactive compounds and antioxidant properties in Cape gooseberry (Physalis peruviana L.).

PubMed

Bravo, Karent; Sepulveda-Ortega, Stella; Lara-Guzman, Oscar; Navas-Arboleda, Alejandro A; Osorio, Edison

2015-05-01

Cape gooseberry (Physalis peruviana) is an exotic fruit highly valued for its organoleptic properties and bioactive compounds. Considering that the presence of phenolics and ascorbic acid could contribute to its functional capacity, it is important to investigate the quality parameters, bioactive contents and functional properties with respect to genotype and ripening time. In this study the genotype effect was evaluated in 15 cultivars for two different harvest times. Changes during maturation were recorded in two commercial cultivars within seven levels of maturity. Multivariate statistical analysis suggested that phenolic content and ORAC value were mainly affected by harvest time and that ascorbic acid content and DPPH level were mainly affected by genotype. In addition, acidity, phenolic content, ORAC value and inhibition of LDL oxidation decreased with maturity, but soluble solids content, ascorbic acid content, β-carotene content and DPPH-scavenging activity were higher in mature fruits. The phenolic content, ascorbic acid content and antioxidant properties of Cape gooseberry fruit were strongly affected by cultivar, harvest time and maturity state. Consequently, the harvest time must be scheduled carefully to gain the highest proportion of bioactive compounds according to the specific cultivar and the environment where it is grown. © 2014 Society of Chemical Industry.

Reduction of hydrogen peroxide-induced erythrocyte damage by Carica papaya leaf extract

PubMed Central

Okoko, Tebekeme; Ere, Diepreye

2012-01-01

Objective To investigate the in vitro antioxidant potential of Carica papaya (C. papaya) leaf extract and its effect on hydrogen peroxide-induced erythrocyte damage assessed by haemolysis and lipid peroxidation. Methods Hydroxyl radical scavenging activities, hydrogen ion scavenging activity, metal chelating activity, and the ferrous ion reducing ability were assessed as antioxidant indices. In the other experiment, human erythrocytes were treated with hydrogen peroxide to induce erythrocyte damage. The extract (at various concentrations) was subsequently incubated with the erythrocytes and later analysed for haemolysis and lipid peroxidation as indices for erythrocyte damage. Results Preliminary investigation of the extract showed that the leaf possessed significant antioxidant and free radical scavenging abilities using in vitro models in a concentration dependent manner (P<0.05). The extract also reduced hydrogen peroxide induced erythrocyte haemolysis and lipid peroxidation significantly when compared with ascorbic acid (P<0.05). The IC50 values were 7.33 mg/mL and 1.58 mg/mL for inhibition of haemolysis and lipid peroxidation, respectively. In all cases, ascorbic acid (the reference antioxidant) possessed higher activity than the extract. Conclusions The findings show that C. papaya leaves possess significant bioactive potential which is attributed to the phytochemicals which act in synergy. Thus, the leaves can be exploited for pharmaceutical and nutritional purposes. PMID:23569948

Reduction of hydrogen peroxide-induced erythrocyte damage by Carica papaya leaf extract.

PubMed

Okoko, Tebekeme; Ere, Diepreye

2012-06-01

To investigate the in vitro antioxidant potential of Carica papaya (C. papaya) leaf extract and its effect on hydrogen peroxide-induced erythrocyte damage assessed by haemolysis and lipid peroxidation. Hydroxyl radical scavenging activities, hydrogen ion scavenging activity, metal chelating activity, and the ferrous ion reducing ability were assessed as antioxidant indices. In the other experiment, human erythrocytes were treated with hydrogen peroxide to induce erythrocyte damage. The extract (at various concentrations) was subsequently incubated with the erythrocytes and later analysed for haemolysis and lipid peroxidation as indices for erythrocyte damage. Preliminary investigation of the extract showed that the leaf possessed significant antioxidant and free radical scavenging abilities using in vitro models in a concentration dependent manner (P<0.05). The extract also reduced hydrogen peroxide induced erythrocyte haemolysis and lipid peroxidation significantly when compared with ascorbic acid (P<0.05). The IC50 values were 7.33 mg/mL and 1.58 mg/mL for inhibition of haemolysis and lipid peroxidation, respectively. In all cases, ascorbic acid (the reference antioxidant) possessed higher activity than the extract. The findings show that C. papaya leaves possess significant bioactive potential which is attributed to the phytochemicals which act in synergy. Thus, the leaves can be exploited for pharmaceutical and nutritional purposes.

Screening of various botanical extracts for antioxidant activity using DPPH free radical method.

PubMed

Waqas, Muhammad Khurram; Saqib, Najam-Us; Rashid, Saeed-Ur; Shah, Pervaiz Akhtar; Akhtar, Naveed; Murtaza, Ghulam

2013-01-01

Aiming at the exploration of herbal use by society, crude extracts of the seeds of some commonly used medicinal plants (Vitis vinifera, Tamarindus indica and Glycin max) were screened for their free radical scavenging properties using ascorbic acid as standard antioxidant. Free radical scavenging activity was evaluated using 1,1-diphenyl-2-picrylhydrazyl (DPPH) free radical. The overall antioxidant activity of grape seeds (Vitis vinifera) was the strongest, followed in descending order by soybean (Glycin max) and tamarind (Tamarindus indica). The seeds extract of Vitis vinifera, Glycin max and Tamarindus indica showed 85.61%, 83.45% and 79.26%, DPPH scavenging activity respectively.

Anthocyanins, antioxidative, and antimicrobial properties of American cranberry (Vaccinium macrocarpon Ait.) and their press cakes.

PubMed

Viskelis, P; Rubinskiene, M; Jasutiene, I; Sarkinas, A; Daubaras, R; Cesoniene, L

2009-03-01

Amounts of total phenolics, anthocyanins, and ascorbic acid in 4 American cranberry varieties harvested at 4 stages of maturity were measured. The larger amount of phenolic compounds was found in berries of "Black Veil" cultivar (504 mg/100 g) at II stage of maturity. Significantly larger amounts of anthocyanins were determined in the overripe berries of the cultivars "Ben Lear" and "Black Veil." The amount of ascorbic acid in berries increased during ripening from I to III stage, and slightly decreased in the overripe berries. The biggest quantities of ascorbic acid were found in the ripe berries of "Ben Lear" cultivar (15.8 mg/100 g). The distribution of anthocyanins pigments was determined by HPLC-UV/MS in mature berries. The composition of individual anthocyanins in berries was quite similar in all the studied cranberry cultivars. While skins of cranberries are rich in anthocyanins and other phenolic compounds, the extracts of the by-products of cranberries juice-berry cakes, were analyzed and obtained results were compared with the properties of extracts made from whole berries. The anthocyanins and total phenolics content, radical scavenging activity, antimicrobial activity of the whole berries, and their press cakes extracts were measured. All investigated extracts from berries and their press cakes showed good radical scavenging activity and revealed antimicrobial properties. It was found that Bacillus cereus (ATCC 10876) and Micrococcus luteus (ATCC 9341) were the most sensitive among 10 tested Gram-negative and Gram-positive bacteria.

Characterization of the activity of L-ascorbic acid 2-[3,4-dihydro-2,5,7,8-tetramethyl-2-(4,8,12-trimethyltridecyl)-2H-1-be nzopyran-6-yl-hydrogen phosphate] potassium salt in hydroxyl radical elimination.

PubMed

Tomita, T; Kashima, M; Tsujimoto, Y

2000-03-01

The effect of L-ascorbic acid 2-[3,4-dihydro-2,5,7,8-tetramethyl-2-(4,8,12-trimethyltridecyl)-2H -1-benzopyran-6-yl-hydrogen phosphate] potassium salt (EPC-K1) on hydroxyl radical (*OH) elimination was studied using electron spin resonance (ESR) and spectrophotometric experiments. The addition of EPC-K, and *OH scavengers eliminated the *OH generated from Cu2+/H2O2, Fe2+/H2O2 and H2O2/UV-irradiation reaction systems. However, in competitive reactions using different concentrations of a spin-trap agent, the addition of the *OH scavenger altered the IC50 values, whereas the addition of EPC-K1 and a metal chelater did not change the value in the Cu2+/H2O2 and Fe2+/H2O2 reaction systems. The addition of EPC-K1 and metal chelater changed the ESR signal for free Cu2+. The spectrophotometric experiments confirmed that the addition of EPC-K1 and metal chelater altered the absorption spectra due to CuCl2 and FeSO4, whereas the *OH scavenger did not alter the spectra. Therefore, it was demonstrated that EPC-K, has the ability both to scavenge *OH directly and to inhibit the generation of *OH by the chelation of Cu2+ and Fe2+.

Antioxidant and antimicrobial capacity of several monofloral Cuban honeys and their correlation with color, polyphenol content and other chemical compounds.

PubMed

Alvarez-Suarez, Jose M; Tulipani, Sara; Díaz, Daimy; Estevez, Yadiley; Romandini, Stefania; Giampieri, Francesca; Damiani, Elisabetta; Astolfi, Paola; Bompadre, Stefano; Battino, Maurizio

2010-01-01

Several monofloral Cuban honeys were analyzed to determine their total phenolic, flavonoid, ascorbic acid, amino acid, protein and carotenoid contents as well as their radical-scavenging activity and antimicrobial capacities. The total phenolic, flavonoid and carotenoid contents varied considerably, and the highest values were obtained for Linen vine (Govania polygama (Jack) Urb) honey, which is classified as an amber honey. The highest amino acid content was found in Morning glory (Ipomoea triloba L.) while Liven vine had the highest protein content. Similarly Linen vine honey had the highest antioxidant activity while the lowest was found in Christmas vine (Turbina corymbosa (L.) Raf). Ascorbic acid was absent. Hydroxyl radical formation was studied by EPR and spin trapping, and it was found in all honeys tested. The antimicrobial activity was screened using two Gram-positive and Gram-negative bacteria. S. aureus was the most sensitive microorganism while Pseudomonas aeruginosa presented higher minimum active dilution values. Bacillus subtilis and Escherichia coli were both moderately sensitive to honey antimicrobial activity. A correlation between radical-scavenging activity and total phenolic content was found. Correlation existed also between color vs phenolics content, vs flavonoid content or between phenolic vs flavonoid. Copyright (c) 2010 Elsevier Ltd. All rights reserved.

Polyphenol oxidase activity and antioxidant properties of Yomra apple (Malus communis L.) from Turkey.

PubMed

Can, Zehra; Dincer, Barbaros; Sahin, Huseyin; Baltas, Nimet; Yildiz, Oktay; Kolayli, Sevgi

2014-12-01

In this study, firstly, antioxidant and polyphenol oxidase (PPO) properties of Yomra apple were investigated. Seventeen phenolic constituents were measured by reverse phase-high-performance liquid chromatography (RP-HPLC). Total phenolic compounds (TPCs), ferric reducing antioxidant power (FRAP) and 2, 2-diphenyl-1-picrylhydrazyl radical (DPPH) scavenging activities were performed to measure antioxidant capacity. Some kinetic parameters (Km, Vmax), and inhibition behaviors against five different substrates were measured in the crude extract. Catechin and chlorogenic acid were found as the major components in the methanolic extract, while ferulic acid, caffeic acid, p-hydroxybenzoic acid, quercetin and p-coumaric acid were small quantities. Km values ranged from 0.70 to 10.10 mM in the substrates, and also 3-(4-hydroxyphenyl) propanoic acid (HPPA) and L-DOPA showed the highest affinity. The inhibition constant of Ki were ranged from 0.05 to 14.90 mM against sodium metabisulphite, ascorbic acid, sodium azide and benzoic acid, while ascorbic acid and sodium metabisulphite were the best inhibitors.

Antioxidant Activities of Achyranthes japonica Nakai Extract and Its Application to the Pork Sausages.

PubMed

Park, J H; Kang, S N; Shin, D; Hur, I C; Kim, I S; Jin, S K

2013-02-01

Influence of Achyranthes japonica Nakai Extract (AJNE) on properties of pork sausages were studied in the present investigation. AJNE was added to sausages alone or in combination with ascorbic acid to obtain a comparative analysis on properties of control and ascorbic acid added-sausages. Results showed that addition of 0.05% AJNE led to a decrease in color L* and whiteness (W), and an increase in color b* of pork sausage samples (p<0.05). Although color a* of pork sausages containing AJNE was not significantly different, ascorbic acid added-sausages were highest amongst other treatments (p<0.05). Sausages containing AJNE had lower non-heme iron values and peroxide value (POV) than control sausages (p<0.05); however, high nitrosomyoglobin content was observed in AJNE added-sausages (p<0.05). Ascorbic acid led to a decrease in residual nitrite concentration of sausages (p<0.05), but no difference was found in AJNE added-sausages. Free radical scavenging analysis showed that AJNE did not affect 1,1-diphenyl -2-picrylhydrazyl (DPPH) activity of sausages, whereas ascorbic acid added-sausages showed relatively higher activity among the samples (p<0.05). Addition of AJNE had no influence on texture properties of sausages. In sensory evaluation, AJNE treatment had significant effects on color (p<0.05), but no significant effects on aroma, flavor, springiness, juiciness, and overall acceptability. In conclusion, the addition of AJNE, as a natural supplement may offer natural antioxidants for pork sausages, and appears to be particularly effective in inducing changes in non-heme iron concentration, POV value and nitrosomyglobin content.

Antioxidant Activities of Achyranthes japonica Nakai Extract and Its Application to the Pork Sausages

PubMed Central

Park, J. H.; Kang, S. N.; Shin, D.; Hur, I. C.; Kim, I. S.; Jin, S. K.

2013-01-01

Influence of Achyranthes japonica Nakai Extract (AJNE) on properties of pork sausages were studied in the present investigation. AJNE was added to sausages alone or in combination with ascorbic acid to obtain a comparative analysis on properties of control and ascorbic acid added-sausages. Results showed that addition of 0.05% AJNE led to a decrease in color L* and whiteness (W), and an increase in color b* of pork sausage samples (p<0.05). Although color a* of pork sausages containing AJNE was not significantly different, ascorbic acid added-sausages were highest amongst other treatments (p<0.05). Sausages containing AJNE had lower non-heme iron values and peroxide value (POV) than control sausages (p<0.05); however, high nitrosomyoglobin content was observed in AJNE added-sausages (p<0.05). Ascorbic acid led to a decrease in residual nitrite concentration of sausages (p<0.05), but no difference was found in AJNE added-sausages. Free radical scavenging analysis showed that AJNE did not affect 1,1-diphenyl -2-picrylhydrazyl (DPPH) activity of sausages, whereas ascorbic acid added-sausages showed relatively higher activity among the samples (p<0.05). Addition of AJNE had no influence on texture properties of sausages. In sensory evaluation, AJNE treatment had significant effects on color (p<0.05), but no significant effects on aroma, flavor, springiness, juiciness, and overall acceptability. In conclusion, the addition of AJNE, as a natural supplement may offer natural antioxidants for pork sausages, and appears to be particularly effective in inducing changes in non-heme iron concentration, POV value and nitrosomyglobin content. PMID:25049789

Inhibitory action on the production of advanced glycation end products (AGEs) and suppression of free radicals in vitro by a Sri Lankan polyherbal formulation Nawarathne Kalka.

PubMed

Fernando, Chamira Dilanka; Karunaratne, Diyathi Tharindhi; Gunasinghe, Sachith Dilshan; Cooray, M C Dilusha; Kanchana, Prabuddhi; Udawatte, Chandani; Perera, Pathirage Kamal

2016-07-08

Advanced glycation end products (AGEs) and free radicals are inflammatory mediators and are implicated in many diseases such as diabetes, cancer, rheumatoid arthritis etc. Multi targeted poly herbal drug systems like Nawarathne Kalka (NK) are able to quench the overall effect of these mediators as they contain good combinations of phytochemicals that have least side effects in contrast to modern medicinal drugs. The objectives of this study were to evaluate phytochemical composition, free radical scavenging activity, cytotoxicity and the inhibitory action on the formation of AGEs by aqueous extract of NK. Total phenolic content (TPC) and total flavonoid content (TFC) were determined using Folin ciocalteu method and aluminium chloride assay respectively. Free radical scavenging activity was assessed by DPPH radical scavenging assay (DRSA), phosphomolybdenum reduction antioxidant assay (PRAA) and nitric oxide (NO) scavenging assay. Brine Shrimp Lethality (BSL) bioassay was performed as preliminary screening for cytotoxic activity. Inhibitory action on AGE formation was evaluated using fructose mediated glycation of bovine serum albumin using fluorescence spectroscopic method. The TPC and TFC were 75.1 ± 3.0 mg/g gallic acid equivalents and 68.7 ± 7.8 mg/g epigallocatechin gallate equivalents. The DRSA yielded EC50 of 19.15 ± 2.24 μg mL(-1) for NK. DRSA of NK extract was greater than butylated hydroxy toluene (EC50 = 96.50 ± 4.51 μg mL(-1)) but lesser than L-ascorbic acid (EC50 = 5.60 ± 0.51 μg mL(-1)). The total antioxidant capacity of NK as evidenced by PRAA was 106.4 ± 8.2 mg/g L-ascorbic acid equivalents. NK showed EC50 value of 99.3 ± 8.4 μg mL(-1) in the NO scavenging assay compared to the standard ascorbic acid (EC50 = 7.3 ± 0.3 μg mL(-1)). The extract indicated moderate cytotoxic activity in the BSL bioassay. The extract showed effective inhibitory action on the formation of AGEs with EC50 values of 116 ± 19 μg mL(-1), 125 ± 35 μg mL(-1) and 84 ± 28 μg mL(-1) in data obtained over three consecutive weeks respectively. Comparatively the reference standard, aminoguanidine at a concentration of 500 μg mL(-1) demonstrated 65 % inhibition on the formation of AGE after one week of sample incubation. The results proved the potential of NK as a free radical scavenger, moderate cytotoxic agent and an inhibitor on the formation of advanced glycation end-products.

[Study of scavenging activity of sorghum pigment to hydroxyl free radicals by fluorimetry].

PubMed

Zhang, Hai-rong; Wang, Wen-yan

2007-03-01

A natural product, sorghum pigment, consists of a number of important flavonoid derivatives, occurrs on the seed capsules or in the stems of many sorghums, and is widely applied in different fields of food, cosmetic and dyeing industries, It is important for scavenging hydroxyl free radicals and protection of human healthiness. Scavenging capacities of hydroxyl free radicals with sodium nitrite, quercetin and sorghum pigment were comparatively researched by fluorimetry, and the model of hydroxyl free radicals produced is based on the reaction of Cu2+ -catalyzed oxidation of ascorbic acid in the presence of hydrogen peroxide. The hydroxyl radicals react with benzoic acid, forming a fluorescent product, and the fluorescence intensity was determined by the concentration of hydroxybenzoic acid. The experimental results show that the sodium nitrite, quercetin and sorghum pigment have a quantity-effect relationship for scavenging hydroxyl free radicals, and sodium nitrite and quercetin in comparison with sorghum pigment have high antioxidant capacity. Finally, the quenching mechanisms were explored with sodium nitrite, sorghum pigment, and quercetin respectively. The sorghum pigment and sodium nitrite feature a dynamic quenching processes, while quercetin shows a static quenching processes. A reference method was provided for reasonable exploitation and utilization of sorghum pigment.

Extracts and Constituents of Rubus chingii with 1,1-Diphenyl-2-picrylhydrazyl (DPPH) Free Radical Scavenging Activity

PubMed Central

Ding, Hsiou-Yu

2011-01-01

The 1,1-diphenyl-2-picrylhydrazyl (DPPH) free radical scavenging activity of the fruits of Rubus chingii was studied in vitro. Ethanolic extract, ethyl acetate and n-butanol fractions from dried R. chingii fruits revealed strong DPPH free radical scavenging activity with IC50 values of 17.9, 3.4 and 4.0 μg/mL, respectively. The ethyl acetate and n-butanol fractions were further purified by a combination of silica gel chromatography, Lobar RP-8 chromatography, and high-pressure liquid chromatography (HPLC). Nine compounds were isolated, where methyl (3-hydroxy-2-oxo-2,3-dihydroindol-3-yl)-acetate (2), vanillic acid (5), kaempferol (7), and tiliroside (9) showed stronger DPPH free radical scavenging activity than that of ascorbic acid (131.8 μM) with IC50 values of 45.2, 34.9, 78.5, and 13.7 μM, respectively. In addition, rubusine (1) is a new compound discovered in the present study and methyl (3-hydroxy-2-oxo-2,3-dihydroindol-3-yl)-acetate (2), methyl dioxindole-3-acetate (3), and 2-oxo-1,2-dihydroquinoline-4-carboxylic acid (4) were isolated from the fruits for the first time. PMID:21747716

Serum alpha-tocopherol and ascorbic acid concentrations in Type 1 and Type 2 diabetic patients with and without angiopathy.

PubMed

Skrha, Jan; Prázný, Martin; Hilgertová, Jirina; Weiserová, Hana

2003-03-01

Alpha-tocopherol and ascorbic acid form a part of scavenger system influencing the level of oxidative stress in diabetes mellitus. The aim of this study was to evaluate serum concentrations of alpha-tocopherol and ascorbic acid in Type 1 and Type 2 diabetes mellitus and to compare them with the presence of vascular complications as well as with oxidative stress and endothelial dysfunction. A total of 38 Type 1 and 62 Type 2 diabetic patients were subdivided into those with and without angiopathy. Serum alpha-tocopherol and ascorbic acid concentrations were estimated in all patients and in 38 healthy persons. Their results were compared with diabetes control, with oxidative stress measured by plasma malondialdehyde and with endothelial dysfunction estimated by serum N-acetyl-beta-glucosaminidase activity. In addition, the differences in biochemical variables were compared between patients with and without angiopathy. Serum alpha-tocopherol related to the sum of cholesterol and triglyceride concentrations (AT/CHT ratio) was significantly lower in diabetic patients with macroangiopathy than in those without vascular changes (p<0.05). Serum ascorbic acid levels were significantly lower only in Type 2 diabetic patients with macroangiopathy as compared with healthy controls as well as with patients without vascular disease (p<0.01). Positive relationship was observed between serum alpha-tocopherol and cholesterol or triglyceride concentrations in both Type 1 and Type 2 diabetic patients. The presence of oxidative stress together with endothelial dysfunction measured by N-acetyl-beta-glucosaminidase activity was accompanied by lower AT/CHT ratio (p<0.005) in Type 2 diabetic patients. Diabetic patients with proven angiopathy or with advanced oxidative stress and endothelial dysfunction have significantly lower AT/CHT ratio and ascorbic acid concentration in serum. Their low concentrations may participate at the increased level of oxidative stress in these individuals.

[Study on scavenging activity to DPPH free radical of different polarity components in Guizhou Miao medicine "bod zangd dak"].

PubMed

Du, Hong-zhi; Nong, Heng; Dong, Li-sha; Li, Jia-li; Liu, Ming; He, Xi-cheng; Zhang, Jing

2015-06-01

The paper is aimed to search more natural plant antioxidants and further research and develop new medicinal plant resources in Guizhou. The Guizhou special miao medicine "bod zangd dak" was extracted with 60% ethanol. The antioxidant activity of the different polarity components separated from the extract was tested by DPPH method with ascorbic acid as positive control. The results showed that the IC50 of the different polarity components was as following: ascorbic acid (0.033 4 g x L(-1)) < ethyl acetate components (0.052 3 g x L(-1)) < total tannins components (0.054 9 g x L(-1)) < 60% ethanol extraction components (0.076 7 g x L(-1)) < butanol extraction components (0.110 g x L(-1)) < water-soluble polysaccharides components (0.168 g x L(-1)) < water extraction components (0.174 g x L(-1)) < water components after extraction (0.226 g x L(-1)) < total polysaccharides components (0.645 g x L(-1)). It is concluded that the different polarity components have different free radical scavenging activity and that provides a scientific basis for further search of the active ingredients and the activive mechanism.

Bioactive Compounds and Fruit Quality of Green Sweet Pepper Grown under Different Colored Shade Netting during Postharvest Storage.

PubMed

Mashabela, Madonna N; Selahle, Kamogelo M; Soundy, Puffy; Crosby, Kevin M; Sivakumar, Dharini

2015-11-01

In this study, influence of 3 types of photo-selective nets (pearl, red and yellow) and a standard black net on marketable yield, fruit quality and bioactive compounds after postharvest storage was investigated. Percentage marketable fruits were higher in green sweet peppers produced under the pearl nets. Fruits produced under the pearl nets showed higher fruit mass, firmness, chlorophyll content, ascorbic acid content, antioxidant scavenging activity after postharvest storage. Red/far red photon ratio under the pearl net could have improved the ascorbic acid content and the antioxidant scavenging activity in green peppers. Green sweet peppers grown under the pearl nets had higher hue values and maintained green color longer. Our results showed the impact of modified light quality on the bioactive compounds of green sweet pepper during postharvest storage. Green sweet peppers are rich in phytochemicals. Marketability of green sweet peppers is affected partially due to ripening after postharvest storage and decay. Maintenance of green color, fruit mass, firmness, and nutritional composition are important parameters that attract consumers. This research shows the influence of light quality during production on the fruit quality parameters and bioactive compounds after postharvest storage. © 2015 Institute of Food Technologists®

Ascorbic Acid Prevents VEGF-induced Increases in Endothelial Barrier Permeability

PubMed Central

Ulker, Esad; Parker, William H.; Raj, Amita; Qu, Zhi-chao; May, James M.

2015-01-01

Vascular endothelial growth factor (VEGF) increases endothelial barrier permeability, an effect that may contribute to macular edema in diabetic retinopathy. Since vitamin C, or ascorbic acid, can tighten the endothelial permeability barrier, we examined whether it could prevent the increase in permeability due to VEGF in human umbilical vein endothelial cells (HUVECs). As previously observed, VEGF increased HUVEC permeability to radiolabeled inulin within 60 min in a concentration-dependent manner. Loading the cells with increasing concentrations of ascorbate progressively prevented the leakage caused by 100 ng/ml VEGF, with a significant inhibition at 13 μM and complete inhibition at 50 μM. Loading cells with 100 μM ascorbate also decreased basal generation of reactive oxygen species and prevented the increase caused by both 100 ng/ml VEGF. VEGF treatment decreased intracellular ascorbate by 25%, thus linking ascorbate oxidation to its prevention of VEGF-induced barrier leakage. The latter was blocked by treating the cells with 60 μM L-NAME (but not D-NAME) as well as by 30 μM sepiapterin, a precursor of tetrahydrobiopterin that is required for proper function of endothelial nitric oxide synthase (eNOS). These findings suggest that VEGF-induced barrier leakage uncouples eNOS. Ascorbate inhibition of the VEGF effect could thus be due either to scavenging superoxide or to peroxynitrite generated by the uncoupled eNOS, or more likely to its ability to recycle tetrahydrobiopterin, thus avoiding enzyme uncoupling in the first place. Ascorbate prevention of VEGF-induced increases in endothelial permeability opens the possibility that its repletion could benefit diabetic macular edema. PMID:26590088

Prevention of acetic acid-induced colitis by desferrithiocin analogs in a rat model.

PubMed

Bergeron, Raymond J; Wiegand, Jan; Weimar, William R; Nguyen, John Nhut; Sninsky, Charles A

2003-02-01

Iron contributes significantly to the formation of reactive oxygen species via the Fenton reaction. Therefore, we assessed whether a series of desferrithiocin analogs, both carboxylic acids and hydroxamates, could (1) either promote or diminish the iron-mediated oxidation of ascorbate, (2) quench a model radical species, 2,2'-azinobis(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS+), and (3) when applied topically, prevent acetic acid-induced colitis in rats. Surprisingly, most of the desferrithiocin analogs inhibited the Fenton reaction to an approximately equivalent degree; however, substantial differences were observed in the capacity of the analogs to scavenge the model radical cation. Four carboxylic acid desferrithiocin analogs and their respective N-methylhydroxamates were tested along with desferrioxamine and Rowasa, a currently accepted topical therapeutic agent for inflammatory bowel disease (IBD), in a rodent model of acetic acid-induced colitis. The colonic damage was quantitated by two independent measurements. Although neither radical scavenging nor prevention of Fenton chemistry was a definitive predictor of in vivo efficacy, the overall trend is that desferrithiocin analogs substituted with an N-methylhydroxamate in the place of the carboxylic acid are both better free radical scavengers and more active against acetic acid-induced colitis. These results represent an intriguing alternative avenue to the development of improved IBD therapeutic agents.

Phytochemical composition and in vitro pharmacological activity of two rose hip (Rosa canina L.) preparations.

PubMed

Wenzig, E M; Widowitz, U; Kunert, O; Chrubasik, S; Bucar, F; Knauder, E; Bauer, R

2008-10-01

The aim of the present study was to compare powdered rose hip with and without fruits (Rosae pseudofructus cum/sine fructibus, Rosa canina L., Rosaceae) with regard to their phytochemical profile and their in vitro anti-inflammatory and radical-scavenging properties. The two powders were subsequently extracted with solvents of increasing polarity and tested for inhibition of cyclooxygenase (COX-1, COX-2) and of 5-LOX-mediated leukotriene B(4) (LTB(4)) formation as well as for DPPH-radical-scavenging capacity. While the water and methanol extracts were inactive in the COX-1, COX-2 and LTB(4) inhibition assays, the n-hexane and the dichloromethane extracts inhibited all three enzymes. In the active extracts, the triterpenoic acids ursolic acid, oleanolic acid and betulinic acid were identified, although only in minute amounts. Furthermore, oleic, linoleic and alpha-linolenic acid were identified apart from several saturated fatty acids. Even though unsaturated fatty acids are known to be good inhibitors of COX-1, COX-2 and LT formation, no clear correlation between their concentration in the extracts and their activity was found. We suggest that other, yet unidentified, lipophilic constituents might play a more important role for the observed in vitro inhibitory activity on arachidonic acid metabolism. Some of the extracts also showed considerable DPPH radical scavenging activity, the methanolic extracts being most potent. The radical scavenging activity of the extracts correlated very well with their total phenolic content, while ascorbic acid contributes only little to the radical-scavenging activity due to its low concentration present in the extracts. In summary, extracts derived from powdered rose hip without fruits were more effective in all assays carried out compared with extracts derived from powdered rose hip with fruits.

Amoebicidal, antimicrobial and in vitro ROS scavenging activities of Tunisian Rubus ulmifolius Schott, methanolic extract.

PubMed

Hajaji, Soumaya; Jabri, Mohamed-Amine; Sifaoui, Ines; López-Arencibia, Atteneri; Reyes-Batlle, María; B'chir, Fatma; Valladares, Basilio; Pinero, José E; Lorenzo-Morales, Jacob; Akkari, Hafidh

2017-12-01

The present study aimed to evaluate the activity of methanolic extract of Rubus ulmifolius Schott against the Acanthamoeba castellani Neff Strain as well as its antioxidant and antimicrobial effects. The tested extract has a good amoebicidal activity with low IC 50 (61.785 ± 1.322 μg/ml) and also has significant activity against both Gram-positive (S. aureus, S. agalactiae) and Gram-negative bacteria (E. coli, S. typhimurium) and against C. albicans. The inhibition zones diameters (IZD) and minimal inhibitory concentration (MIC) values were in the range of 22.5-50 mm and 02.29-4.76 mg ml -1 , respectively. In the other hand, the in vitro ROS scavenging activity was evaluated, the tested extract exhibited a good effect on the ·OH radical (89.99% at a concentration of 100 μg/ml) when compared to the ascorbic acid (68.81%). Moreover, the inhibition percentage of superoxide generation by R. ulmifolius extract at 100 μg/ml was greater than ascorbic acid (79.55; 64.79%, respectively). Also, the tested extract showed a high percentage of H 2 O 2 scavenging activity (99.95% at 100 μg/ml). Our findings suggest that R. ulmifolius could be a potential source of natural antioxidant in preventing many diseases associated with oxidative stress, amoebic and bacterial infections. Copyright © 2017 Elsevier Inc. All rights reserved.

How the multiple antioxidant properties of ascorbic acid affect lipid oxidation in oil-in-water emulsions.

PubMed

Uluata, Sibel; McClements, D Julian; Decker, Eric A

2015-02-18

Lipid oxidation is a serious problem for oil-containing food products because it negatively affects shelf life and nutritional composition. An antioxidant strategy commonly employed to prevent or delay oxidation in foods is to remove oxygen from the closed food-packaging system. An alternative technique is use of an edible oxygen scavenger to remove oxygen within the food. Ascorbic acid (AA) is a particularly promising antioxidant because of its natural label and multiple antioxidative functions. In this study, AA was tested as an oxygen scavenger in buffer and an oil-in-water (O/W) emulsion. The effects of transition metals on the ability of AA to scavenge oxygen were determined. Headspace oxygen decrease less than 1% in the medium-chain triacylglycerol (MCT) O/W emulsion system (pH 3 and 7). AA was able to almost completely remove dissolved oxygen (DO) in a buffered solution. Transition metals (Fe(2+) and Cu(+)) significantly accelerated the degradation of AA; however, iron and copper only increased DO depletion rates, by 10.6-16.4% from day 1 to 7, compared to the control. AA (2.5-20 mM) decreased DO in a 1% O/W emulsion system 32.0-64.0% and delayed the formation of headspace hexanal in the emulsion from 7 to over 20 days. This research shows that, when AA is used in an O/W emulsion system, oxidation of the emulsion system can be delay by multiple mechanisms.

Prospecting Russula senecis: a delicacy among the tribes of West Bengal

PubMed Central

Khatua, Somanjana; Dutta, Arun Kumar

2015-01-01

Russula senecis, a worldwide distributed mushroom, is exclusively popular among the tribal communities of West Bengal for food purposes. The present study focuses on its reliable taxonomic identification through macro- and micro-morphological features, DNA barcoding, confirmation of its systematic placement by phylogenetic analyses, myco-chemicals and functional activities. For the first time, the complete Internal Transcribed Spacer region of R. senecis has been sequenced and its taxonomic position within subsection Foetentinae under series Ingratae of the subgen. Ingratula is confirmed through phylogenetic analysis. For exploration of its medicinal properties, dried basidiocarps were subjected for preparation of a heat stable phenol rich extract (RusePre) using water and ethanol as solvent system. The antioxidant activity was evaluated through hydroxyl radical scavenging (EC50 5 µg/ml), chelating ability of ferrous ion (EC50 0.158 mg/ml), DPPH radical scavenging (EC50 1.34 mg/ml), reducing power (EC50 2.495 mg/ml) and total antioxidant activity methods (13.44 µg ascorbic acid equivalent/mg of extract). RusePre exhibited antimicrobial potentiality against Listeria monocytogenes, Bacillus subtilis, Pseudomonas aeruginosa and Staphylococcus aureus. Furthermore, different parameters were tested to investigate its chemical composition, which revealed the presence of appreciable quantity of phenolic compounds, along with carotenoids and ascorbic acid. HPLC-UV fingerprint indicated the probable existence of at least 13 phenolics, of which 10 were identified (pyrogallol > kaempferol > quercetin > chlorogenic acid > ferulic acid, cinnamic acid > vanillic acid > salicylic acid > p-coumaric acid > gallic acid). Result from the present work suggests that the fraction, RusePre, may open novel prospect as a functional ingredient in antioxidant supplements and in drugs to treat infectious disease. PMID:25780764

In vitro antioxidant activity of Retama monosperma (L.) Boiss.

PubMed

Belmokhtar, Zoubir; Harche, Meriem Kaid

2014-01-01

The relationship between the antioxidant activity and the phenolic contents (total polyphenol, flavonoid and condensed tannin) of Retama monosperma (Fabaceae), used commonly in the traditional medicine of Mediterranean regions, was investigated. The antioxidant activities of the various fractions (toluene, chloroform, ethyl acetate and butanol) of the hydromethanolic extract of the seeds, stems and flowers have been evaluated using in vitro 2,2-diphenyl-1-picrylhydrazyl radical (DPPH) radical scavenging activities and Phosphomolybdic acid assays and were compared to ascorbic acid. A significant high Pearson's correlations between flavonoid content and antioxidant activities (r = 0.91) with Phosphomolybdic acid assays and (r = - 0.79) with IC50 DPPH radical scavenging activities. However, there was no correlation between condensed tannin and antioxidant activities. The results obtained in the present study indicate that the ethyl acetate fraction of seeds is a potential source of natural antioxidant for R. monosperma.

Impact of optimised cooking on the antioxidant activity in edible mushrooms.

PubMed

Ng, Zhi Xiang; Tan, Wan Chein

2017-11-01

This study aimed to investigate the effect of four cooking methods with different durations on the in vitro antioxidant activities of five edible mushrooms, namely Agaricus bisporus , Flammulina velutipes , Lentinula edodes , Pleurotus ostreatus and Pleurotus eryngii. Among the raw samples, A. bisporus showed the highest total antioxidant activity (reducing power and radical scavenging), total flavonoid, ascorbic acid and water soluble phenolic contents. Short-duration steam cooking (3 min) increased the total flavonoid and ascorbic acid while prolonged pressure cooking (15 min) reduced the water soluble phenolic content in the mushrooms. The retention of antioxidant value in the mushrooms varied with the variety of mushroom after the cooking process. The cooking duration significantly affected the ascorbic acid in the mushrooms regardless of cooking method. To achieve the best antioxidant values, steam cooking was preferred for F. velutipes (1.5 min), P. ostreatus (4.5 min) and L. edodes (4.5 min) while microwave cooking for 1.5 min was a better choice for A. bisporus . Pressure cooked P. eryngii showed the best overall antioxidant value among the cooked samples. Optimised cooking method including pressure cooking could increase the antioxidant values in the edible mushrooms.

Analysis and characterisation of phytochemicals in mulberry (Morus alba L.) fruits grown in Vojvodina, North Serbia.

PubMed

Natić, Maja M; Dabić, Dragana Č; Papetti, Adele; Fotirić Akšić, Milica M; Ognjanov, Vladislav; Ljubojević, Mirjana; Tešić, Živoslav Lj

2015-03-15

In this study, the polyphenolic profile of 11 Morus alba fruits grown in the Vojvodina region was investigated. Ultra high performance liquid chromatography (UHPLC) coupled with Linear Trap Quadrupole and OrbiTrap mass analyzer, and UHPLC coupled with a diode array detector and a triple-quadrupole mass spectrometer were used for the identification and quantification of the polyphenols, respectively. A total of 14 hydroxycinnamic acid esters, 13 flavonol glycosides, and 14 anthocyanins were identified in the extracts with different distributions and contents according to the sampling. The total phenolic content ranged from 43.84 to 326.29 mg GAE/100g frozen fruit. The radical scavenging capacity (50.18-86.79%), metal chelating ability (0.21-8.15%), ferric ion reducing power (0.03-38.45 μM ascorbic acid) and superoxide anion radical scavenging activity (16.53-62.83%) were assessed. The findings indicated that mulberry polyphenolics may act as potent superoxide anion radical scavengers and reducing agents. Copyright © 2014 Elsevier Ltd. All rights reserved.

In vitro evaluation of antioxidant activity of Cordia dichotoma (Forst f.) bark

PubMed Central

Nariya, Pankaj B.; Bhalodia, Nayan R.; Shukla, Vinay J.; Acharya, Rabinarayan; Nariya, Mukesh B.

2013-01-01

Cordia dichotoma Forst. f. bark, identified as botanical source of Shleshmataka in Ayurvedic pharmacopoeia. Present investigation was undertaken to evaluate possible antioxidant potential of methanolic and butanol extract of C. dichotoma bark. In vitro antioxidant activity of methanolic and butanol extract was determined by 1,1, diphenyl–2, picrylhydrazyl (DPPH) free radical scavenging assay. The extracts were also evaluated for their phenolic contents and antioxidant activity. Phenolic content was measured using Folin–Ciocalteu reagent and was calculated as Gallic acid equivalents. Antiradical activity of methanolic extract was measured by DPPH assay and was compared to ascorbic acid and ferric reducing power of the extract was evaluated by Oyaizu method. In the present study three in vitro models were used to evaluate antioxidant activity. The first two methods were for direct measurement of radical scavenging activity and remaining one method evaluated the reducing power. The present study revealed that the C. dichotoma bark has significant radical scavenging activity. PMID:24049418

In vitro evaluation of antioxidant activity of Cordia dichotoma (Forst f.) bark.

PubMed

Nariya, Pankaj B; Bhalodia, Nayan R; Shukla, Vinay J; Acharya, Rabinarayan; Nariya, Mukesh B

2013-01-01

Cordia dichotoma Forst. f. bark, identified as botanical source of Shleshmataka in Ayurvedic pharmacopoeia. Present investigation was undertaken to evaluate possible antioxidant potential of methanolic and butanol extract of C. dichotoma bark. In vitro antioxidant activity of methanolic and butanol extract was determined by 1,1, diphenyl-2, picrylhydrazyl (DPPH) free radical scavenging assay. The extracts were also evaluated for their phenolic contents and antioxidant activity. Phenolic content was measured using Folin-Ciocalteu reagent and was calculated as Gallic acid equivalents. Antiradical activity of methanolic extract was measured by DPPH assay and was compared to ascorbic acid and ferric reducing power of the extract was evaluated by Oyaizu method. In the present study three in vitro models were used to evaluate antioxidant activity. The first two methods were for direct measurement of radical scavenging activity and remaining one method evaluated the reducing power. The present study revealed that the C. dichotoma bark has significant radical scavenging activity.

Intracellular ascorbate tightens the endothelial permeability barrier through Epac1 and the tubulin cytoskeleton

PubMed Central

Parker, William H.; Rhea, Elizabeth Meredith; Qu, Zhi-Chao; Hecker, Morgan R.

2016-01-01

Vitamin C, or ascorbic acid, both tightens the endothelial permeability barrier in basal cells and also prevents barrier leak induced by inflammatory agents. Barrier tightening by ascorbate in basal endothelial cells requires nitric oxide derived from activation of nitric oxide synthase. Although ascorbate did not affect cyclic AMP levels in our previous study, there remains a question of whether it might activate downstream cyclic AMP-dependent pathways. In this work, we found in both primary and immortalized cultured endothelial cells that ascorbate tightened the endothelial permeability barrier by ∼30%. In human umbilical vein endothelial cells, this occurred at what are likely physiologic intracellular ascorbate concentrations. In so doing, ascorbate decreased measures of oxidative stress and also flattened the cells to increase cell-to-cell contact. Inhibition of downstream cyclic AMP-dependent proteins via protein kinase A did not prevent ascorbate from tightening the endothelial permeability barrier, whereas inhibition of Epac1 did block the ascorbate effect. Although Epac1 was required, its mediator Rap1 was not activated. Furthermore, ascorbate acutely stabilized microtubules during depolymerization induced by colchicine and nocodazole. Over several days in culture, ascorbate also increased the amount of stable acetylated α-tubulin. Microtubule stabilization was further suggested by the finding that ascorbate increased the amount of Epac1 bound to α-tubulin. These results suggest that physiologic ascorbate concentrations tighten the endothelial permeability barrier in unstimulated cells by stabilizing microtubules in a manner downstream of cyclic AMP that might be due both to increasing nitric oxide availability and to scavenging of reactive oxygen or nitrogen species. PMID:27605450

Comparison of the rates of ozonation of biological antioxidants and oleate and linoleate esters

DOE Office of Scientific and Technical Information (OSTI.GOV)

Giamalva, D.; Church, D.F.; Pryor, W.A.

1985-12-17

The rates of reaction with ozone of some biological antioxidants and simple polyunsaturated fatty acids (PUFA) have been measured in water or in aqueous micellar solutions. At pH 7.0 the rate constants are ca. 10(6) M-1 sec-1 for urate, alpha-tocopherol, and PUFA, and 6 X 10(7) M-1 sec-1 for ascorbate. When ozone-containing air is breathed, ascorbate in the lung may undergo direct ozonation. However, alpha-tocopherol is probably spared direct reaction with ozone because it doesn't effectively compete with PUFA in pulmonary membranes; rather, tocopherol is used to scavenge radicals produced from the ozone-PUFA reaction.

Protective and antioxidative effect of rubropunctatin against oxidative protein damage induced by metal catalyzed reaction.

PubMed

Dhale, Mohan A; Javagal, Manjunatha; Puttananjaiah, Mohan-Kumari H

2018-05-03

Monascus purpureus is known to produce several coloured secondary metabolites. In this study, M. purpureus CFR 410-11 mutant fermented with rice was dried and extracted in hexane for purification of pigment. The purity of the isolated pigment was confirmed by different chromatography techniques. The spectroscopic analysis revealed its structural identity as rubropunctatin. The antioxidant potencies of isolated rubropunctatin were evaluated. Rubropunctatin scavenged 16% 2, 2-diphenyl-1-picrylhydrazyl (DPPH) radical and inhibited 20% superoxide generation at 8 μg/ml concentration. The multiple antioxidant abilities of rubropunctatin were evidenced by its ferric reducing capacity also. The oxidative damage of BSA protein was induced by the metal catalyzed oxidation (MCO) by Fe 2+ /H 2 O 2 . The protective effects of rubropunctatin and M. purpureus (MTCC-410 and CFR 410-11) extracts were compared with glutathione and ascorbic acid. The M. purpureus extracts and rubropunctatin inhibited the formation of carbonyl content and protein oxidation assayed by SDS-PAGE. Rubropunctatin (42-169 μM) efficiently inhibited the protein oxidation compared to glutathione (48-195 μM) and ascorbic acid (85-340 μM) by scavenging the superoxide and hydroxyl radical generated in the system. Copyright © 2018 Elsevier B.V. All rights reserved.

Antioxidant activities of different solvent extracts of Piper retrofractum Vahl. using DPPH assay

NASA Astrophysics Data System (ADS)

Jadid, Nurul; Hidayati, Dewi; Hartanti, Sylviana Rosyda; Arraniry, Byan Arasyi; Rachman, Rizka Yuanita; Wikanta, Wiwi

2017-06-01

Piper retrofractum Vahl., which belongs to the family Piperaceae, is geographically dispersed in tropical region including Indonesia. They are well-known spice possessing high medicinal properties. This study aimed to determine the antioxidant activity of P. retrofractum fruit, extracted with different solvents (methanol, ethyl acetate, n-hexane) using 2,2-diphenyl-1-picrylhydrazyl (DPPH) assay. This research was carried out using different concentrations of methanol, ethyl acetate, and n-hexane extracts, (0, 5, 15, 30, 45, 60 ppm). Ascorbic acid was also used as positive antioxidant control. The percentage of inhibition and IC50 were measured. The results showed that the DPPH free radicals were scavenged by all plant extracts in a concentration dependent manner. Moreover, the IC50 values for DPPH radicals with methanol, ethyl acetate and n-hexane extract of the P. retrofractum Vahl. were found to be 101.74; 66.12 and 57.66 ppm, respectively. Interestingly, the IC50 value of n-hexane extract (57.66 ppm) was lower than ascorbic acid (66.12 ppm), indicating that n-hexane extract was a more potent scavenger of free radicals than methanol and ethyl acetate extracts. Taken together, our results suggested that n-hexane extract of P. Retrofractum Vahl. might contain potential antioxidant compounds.

Cobalt(II) ion as a promoter of hydroxyl radical and possible 'crypto-hydroxyl' radical formation under physiological conditions. Differential effects of hydroxyl radical scavengers.

PubMed

Moorhouse, C P; Halliwell, B; Grootveld, M; Gutteridge, J M

1985-12-13

Co(II) ions react with hydrogen peroxide under physiological conditions to form a 'reactive species' that can hydroxylate aromatic compounds (phenol and salicylate) and degrade deoxyribose to thiobarbituric-acid-reactive material. Catalase decreases the formation of this species but superoxide dismutase or low concentrations of ascorbic acid have little effect. EDTA, present in excess over the Co(II), can accelerate deoxyribose degradation and aromatic hydroxylation. In the presence of EDTA, deoxyribose degradation by the reactive species is inhibited competitively by scavengers of the hydroxyl radical (.OH), their effectiveness being related to their second-order rate constants for reaction with .OH. In the absence of EDTA the scavengers inhibit only at much higher concentrations and their order of effectiveness is changed. It is suggested that, in the presence of EDTA, hydroxyl radical is formed 'in free solution' and attacks deoxyribose or an aromatic molecule. In the absence of EDTA, .OH radical is formed in a 'site-specific' manner and is difficult to intercept by .OH scavengers. The relationship of these results to the proposed 'crypto .OH' radical is discussed.

Effects of short-term anoxia treatment on browning of fresh-cut Chinese water chestnut in relation to antioxidant activity.

PubMed

You, Yanli; Jiang, Yueming; Sun, Jian; Liu, Hai; Song, Lili; Duan, Xuewu

2012-06-01

The effects of short-term anoxia pre-treatment on browning of fresh-cut Chinese water chestnut (CWC), stored at 4°C, in relation to antioxidant activity were investigated. CWC slices were exposed to pure N 2 for 4h and then stored at 4°C for 18d. Anoxia significantly inhibited browning of CWC slices during storage, accompanied by lower contents of malondialdehyde, H 2 O 2 , and lipoxygenase activity. Furthermore, anoxia induced the activities of superoxide dismutase and ascorbate peroxidase, which could benefit scavenging reactive oxygen species and alleviating lipid peroxidation. In addition, better maintenance of reducing power and free-radical-scavenging activities against α,α-diphenyl-β-picrylhydrazy (DPPH), superoxide anions and hydroxyl was observed in N 2 -treated CWC slices, with higher phenolic compounds and ascorbic acid contents. Collectively, these finds suggest that N 2 pre-treatment enhanced enzymatic and non-enzymatic antioxidant activity in CWC slices, and thereby contributed to alleviating lipid peroxidation and maintenance of storage quality. Copyright © 2011 Elsevier Ltd. All rights reserved.

Catalytic therapy of cancer by ascorbic acid involves redox cycling of exogenous/endogenous copper ions and generation of reactive oxygen species.

PubMed

Hadi, S M; Ullah, M F; Shamim, U; Bhatt, S H; Azmi, A S

2010-01-01

Catalytic therapy is a cancer treatment modality based on the generation of reactive oxygen species (ROS) through administration of ascorbate/medicinal herbal extracts and copper. It is known that antioxidants such as ascorbate also exhibit prooxidant activity in the presence of transition metals such as copper. Based on our work and that in the literature, in this review we propose a mechanism for the cytotoxic action of ascorbate against cancer cells. It involves redox cycling of exogenous/endogenous copper ions and the consequent generation of ROS leading to oxidative DNA breakage. Using human peripheral lymphocytes and the Comet assay, we have shown that ascorbic acid is able to cause oxidative breakage in cellular DNA. Such DNA degradation is inhibited by neocuproine (a Cu(I) sequestering agent) and scavengers of ROS indicating that the cellular DNA breakage involves the generation of Cu(I) and formation of ROS. Similar results are also obtained with plant polyphenol antioxidants that are important constituents of medicinal herbal extracts. Copper is an essential component of chromatin and can take part in redox reactions. It is well established that tissue, cellular and serum copper levels are considerably elevated in various malignancies. Therefore, cancer cells may be more subject to electron transfer between copper ions and ascorbate/plant polyphenols to generate ROS. In this review we cite evidence to indicate that in catalytic therapy cytotoxic action against cancer cells involves redox cycling of exogenous/endogenous copper ions. Copyright © 2010 S. Karger AG, Basel.

Antioxidant and anticholinesterase activities of five wild mushroom species with total bioactive contents.

PubMed

Tel, Gulsen; Ozturk, Mehmet; Duru, Mehmet E; Turkoglu, Aziz

2015-06-01

Recently, mushrooms are interesting natural products to be investigated due to exhibiting various bioactivities. This study determines the antioxidant and anticholinesterase activities of various extracts of five wild mushroom species. In addition, the total bioactive contents, namely, ascorbic acid, β-carotene, and lycopene along with phenolic and flavonoid contents were also determined spectrophotometrically. Antioxidant activity was tested by using five complementary tests; namely, β-carotene-linoleic acid, DPPH(•) scavenging, ABTS(•+) scavenging, cupric-reducing antioxidant capacity (CUPRAC), and metal chelating assays. The in vitro anticholinesterase activity was tested against acetylcholinesterase (AChE) and butyrylcholinesterase (BChE) enzymes using the Ellman method. The spectrophotometric methods were used to determine the total phenolic, flavonoid, ascorbic acid, β-carotene, and lycopene contents. The current study has shown that ethyl acetate extracts of Ganoderma lucidum (Curtis) P. Karst (IC50: 1.55 ± 0.05 µg/mL) and Funalia trogii (Berk.) Bondartsev & Singer (IC50: 4.31 ± 0.18 µg/mL) exhibited good lipid peroxidation inhibitory activity. The DPPH, ABTS, and CUPRAC assays supported this activity. The ethyl acetate and methanol extracts of Funalia trogii and Ganoderma lucidum indicated good anticholinesterase activity. Ganoderma lucidum had rich phenolic and flavonoid contents, indicating 98.67 ± 0.32 mg PEs/g extract and 160.38 ± 1.25 mg QEs/g extract, respectively. The results demonstrate that some of the mushroom species tested herein could be used in food and pharmaceutical industries as natural antioxidants.

Phytochemicals and antioxidant activity of fruits and leaves of paprika (Capsicum Annuum L., var. special) cultivated in Korea.

PubMed

Kim, Ji-Sun; Ahn, Jiyun; Lee, Sung-Joon; Moon, Bokyung; Ha, Tae-Youl; Kim, Suna

2011-03-01

The phytochemical composition of carotenoids, tocopherols, free sugars, organic acids, L-ascorbic acid, capsaicinoids, and flavonoids in green and red paprika (GP and RP), and paprika leaves (PL) cultivated in Korea were analyzed. The ethanolic extracts of GP, RP, and PL were obtained with 80% ethanol, and their antioxidative activities were determined by measuring their ABTS and DPPH radical scavenging activities. RP showed the highest contents of capsanthin (58.33 ± 3.91 mg/100 g dry weight) and L-ascorbic acid (1987.25 ± 19.64 mg/100 g dry weight), and main compounds of PL were lutein, chlorophyll, and γ-tocopherol (96.91 ± 14.58, 2136.71 ± 21.11, and 723.49 ± 54.10 mg/100 g dry weight, respectively). RP showed the strongest antioxidant activity (IC(50) = 55.23 ± 6.77 μg/mL in a 2, 2'-azino-di-[3-ethylbenzthiazoline sulphonate] assay and 150.40 ± 8.07 μg/mL in a 2, 2-diphenyl-2-picrylhydrazyl assay), and the antioxidant activity of PL was higher than β-carotene but lower than RP. The results indicate that the amounts of capsanthin and L-ascorbic acid in RP correlate well with antioxidant activity. PL, which has various phytochemicals such as lutein, chlorophyll, and γ-tocopherol, might be used in nutraceuticals and pharmaceuticals for improving human health.

A mushroom-derived amino acid, ergothioneine, is a potential inhibitor of inflammation-related DNA halogenation.

PubMed

Asahi, Takashi; Wu, Xiaohong; Shimoda, Hiroshi; Hisaka, Shinsuke; Harada, Etsuko; Kanno, Tomomi; Nakamura, Yoshimasa; Kato, Yoji; Osawa, Toshihiko

2016-01-01

Myeloperoxidase (MPO)-generated halogenating molecules, such as hypochlorous acid and hypobromous acid (HOBr), in inflammatory regions are postulated to contribute to disease progression. In this study, we showed that ergothioneine (EGT), derived from an edible mushroom, inhibited MPO activity as well as the formation of 8-bromo-2'-deoxyguanosine in vitro. The HOBr scavenging effect of EGT is higher than those of ascorbic acid and glutathione. We initially observed that the administration of Coprinus comatus, an edible mushroom containing a high amount of EGT, inhibited the UV-B-induced inflammatory responses and DNA halogenation, suggesting that EGT is a promising anti-inflammatory agent from mushrooms.

Chemical constituents, radical scavenging activity and enzyme inhibitory capacity of fruits from Cotoneaster pannosus Franch.

PubMed

Les, Francisco; López, Víctor; Caprioli, Giovanni; Iannarelli, Romilde; Fiorini, Dennis; Innocenti, Marzia; Bellumori, Maria; Maggi, Filippo

2017-05-24

Cotoneaster pannosus (Rosaceae) is a semievergreen shrub, producing globose dark red pomes, native to China and widely used as an ornamental plant all over the world. Despite its extensive cultivation, little information is available on the chemical composition and biological activities of its fruits. In this work, the analysis of the chemical composition of C. pannosus fruits, in terms of phenolic components, carotenoids and ascorbic acid by HPLC/DAD, HPLC/ESI-MS and MS/MS as well as in terms of macro- and micro-nutrients was performed. The fruits proved to be a good source of shikimic acid and caffeoylquinic acids, whereas β-carotene, pelargonidin-3-O glucoside and cyanidin-3,5-rutinoside gave an important contribution to the color of the fruit. Both the polar and apolar fruit extracts showed noteworthy radical scavenger activity and inhibitory effects against monoamine oxidase A (MAO-A), tyrosinase (TYR) and α-glucosidase, making C. pannosus red pomes a promising candidate ingredient in functional foods and dietary supplements.

In vitro antioxidant evaluation and total phenolics of methanolic leaf extracts of Nyctanthes arbor-tristis L.

PubMed

Michael, J Savarimuthu; Kalirajan, A; Padmalatha, C; Singh, A J A Ranjit

2013-09-01

To investigate the in vitro antioxidant activity and total phenolic content of the methanolic leaf extract of Nyctanthes arbor-tristis L. (NA). The sample was tested using five in vitro antioxidant methods (1, 1-diphenyl-2-picryl hydrazine radical scavenging activity (DPPH), hydroxyl radical-scavenging activity (-OH), nitric oxide scavenging activity (NO), superoxide radical-scavenging activity, and total antioxidant activity) to evaluate the in vitro antioxidant potential of NA and the total phenolic content (Folin-Ciocalteu method). The extract showed good free radical scavenging property which was calculated as an IC50 value. IC50 (Half maximal inhibitory concentration) of the methanolic extract was found to be 57.93 μg·mL(-1) for DPPH, 98.61 μg·mL(-1) for -OH, 91.74 μg·mL(-1) for NO, and 196.07 μg·mL(-1) for superoxide radical scavenging activity. Total antioxidant capacity of the extract was found to be (1198 ± 24.05) mg ascorbic acid for the methanolic extract. Free radical scavenging activity observed in the extracts of NA showed a concentration-dependent reaction. The in vitro scavenging tested for free radicals was reported to be due to high phenolic content in the leaf extract. The leaf extract of NA showed the highest total phenolic content with a value of 78.48 ± 4.2 equivalent mg TAE/g (tannic acid equivalent). N. arbor-tristis leaf extract exhibited potent free radical scavenging activity. The finding suggests that N. arbor-tristis leaves could be a potential source of natural antioxidant. Copyright © 2013 China Pharmaceutical University. Published by Elsevier B.V. All rights reserved.

Ripening of Pithecellobium dulce (Roxb.) Benth. [Guamúchil] Fruit: Physicochemical, Chemical and Antioxidant Changes.

PubMed

Wall-Medrano, Abraham; González-Aguilar, Gustavo A; Loarca-Piña, Guadalupe F; López-Díaz, José A; Villegas-Ochoa, Mónica A; Tortoledo-Ortiz, Orlando; Olivas-Aguirre, Francisco J; Ramos-Jiménez, Arnulfo; Robles-Zepeda, Ramón

2016-12-01

The fruit of Guamúchil is an excellent source of bioactive compounds for human health although their natural occurrence could be affected by the ripening process. The aim was to evaluate some physicochemical, chemical and antioxidant changes in guamúchil fruit during six ripening stages (I to VI). A defined trend (p ≤ 0.003) was observed for color [°Hue, 109 (light green) to 20 (dark red)], anthocyanins (+571 %), soluble solids (+0.33 o Brix), ash (+16 %), sucrose (-91 %), proanthocyanidins (63 %), ascorbic acid (-52 %) and hydrolysable PC (-21 %). Carotenoids were not detected and chlorogenic acid was the most abundant phenolic compound. Maximal availability of these bioactives per ripening stage (p ≤ 0.03) was as follows: I (protein/ lipids/ sucrose/ proanthocyanidins/ hydrolysable phenolics), II (total sugars/ascorbic acid), III (total phenolics), IV (flavonoids/ chlorogenic acid) and VI (fructose/ glucose/ anthocyanins). Color change was explained by sucrose (β = 0.47) and anthocyanin (β = 0.20) contents (p < 0.001). Radical scavenging capacity (ORAC, DPPH and TEAC) strongly correlated with total PC (r = 0.49-0.65, p ≤ 0.001) but 89 % of ORAC's associated variance was explained by anthocyanin + sucrose + ascorbic acid (p ≤ 0.0001). Guamúchil fruit could be a more convenient source of specific bioactive compounds if harvested at different ripening stages.

Oxygen radical-mediated mutagenic effect of asbestos on human lymphocytes: suppression by oxygen radical scavengers.

PubMed

Korkina, L G; Durnev, A D; Suslova, T B; Cheremisina, Z P; Daugel-Dauge, N O; Afanas'ev, I B

1992-02-01

The mutagenic effect of chrysotile asbestos fibers and zeolite and latex particles on human lymphocytes in whole blood has been studied. It was concluded that their mutagenic activities were mediated by oxygen radicals because they were inhibited by antioxidant enzymes (SOD and catalase) and oxygen radical scavengers (rutin, ascorbic acid, and bemitil). It was proposed that oxygen radicals were released by phagocytes activated upon exposure to mineral dusts and fibers. The study of lucigenin- and luminol-amplified chemiluminescence of peritoneal macrophages stimulated by chrysotile fibers and zeolite and latex particles has shown that their mutagenic action is probably mediated by different oxygen species, namely, by the iron-oxygen complexes (perferryl ions) plus hydrogen peroxide, hydrogen peroxide, and superoxide ion, respectively. From the oxygen radical scavengers studied, rutin was the most effective inhibitor of the mutagenic effect of mineral fibers and dusts.

Flaxseed hull: Chemical composition and antioxidant activity during development.

PubMed

Herchi, Wahid; Al Hujaili, Abdullah D; Sakouhi, Faouzi; Sebei, Khaled; Trabelsi, Hajer; Kallel, Habib; Boukhchina, Sadok

2014-01-01

Changes in the chemical composition and antioxidant activity of flaxseed hull during maturation were investigated. P129 hull variety was studied at four maturation stages (St1, St2, St3, and St4). Significant variation in proximate composition and flaxseed hull oil characteristics were observed. A significant increase in the carbohydrates content of the hull was observed during development. The main methyl esters were linolenic acid (48.95 - 51.52 %), oleic acid (20.27-23.41%) and linoleic acid (15.62-17.70%). The highest polyunsaturated fatty acids (PUFA) were found to be 67.14 % at the first stage of maturity (St1). Flaxseed hull oil was of good quality, containing an abundance of omega-3 essential fatty acids. The iodine value increased, while the saponification value of oil decreased during seed development. The decrease in ascorbic acid content was steady. The maximum level of total phenolic acid content (128.3 mg/100 g oil) was reached at 7 DAF. The antioxidant activity of oilseed was assessed by means of 2, 2-diphenyl-1-picrylhydrazyl (DPPH) radical-scavenging assay. Radical scavenging activity for green hull was 52.74% and mature hull was 69.32%.

Antimutagenic and antioxidant properties of the aqueous extracts of organic and conventional grapevine Vitis labrusca cv. Isabella leaves in V79 cells.

PubMed

Trindade, Cristiano; Bortolini, Giovana Vera; Costa, Bárbara Segalotto; Anghinoni, Joanna Carra; Guecheva, Temenouga Nikolova; Arias, Ximena; Césio, Maria Verónica; Heinzen, Horácio; Moura, Dinara Jaqueline; Saffi, Jenifer; Salvador, Mirian; Henriques, João Antonio Pêgas

2016-01-01

Grapes are one of the most commonly consumed fruit, in both fresh and processed forms; however, a significant amount is disposed of in the environment. Searching for a use of this waste, the antigenotoxic, antimutagenic, and antioxidant activities of aqueous extracts from organic and conventional Vitis labrusca leaves were determined using V79 cells as model. The antigenotoxic activity was analyzed by the alkaline comet assay using endonuclease III and formamidopyrimidine DNA glycosylase enzymes. The antimutagenic property was assessed through the micronucleus (MN) formation, and antioxidant activities were assessed using 2',7'-dichlorodihydrofluorescin diacetate (DCFH-DA) assay and 2,2-diphenyl-1-picrylhydrazyl (DPPH(●)) radical scavenging, as well as with superoxide dismutase (SOD) and catalase (CAT) activity assays. In addition, phenolic content and ascorbic acid levels of both extracts were determined. Data showed that both organic and conventional grapevine leaves extracts possessed antigenotoxic and antimutagenic properties. The extract of organic leaves significantly reduced intracellular reactive oxygen species (ROS) levels in V79 cells, and displayed greater ability for DPPH(●) scavenging and higher SOD and CAT activities than extract from conventional leaves. Further, the extract from organic leaves contained higher phenolic and ascorbic acid concentrations. In summary, extracts from organic and conventional grape leaves induced important in vitro biological effects.

Oral administration of L-arginine in patients with angina or following myocardial infarction may be protective by increasing plasma superoxide dismutase and total thiols with reduction in serum cholesterol and xanthine oxidase

PubMed Central

Tripathi, Pratima; Chandra, M

2009-01-01

Administration of L-arginine has been shown to control ischemic injury by producing nitric oxide which dilates the vessels and thus maintains proper blood flow to the myocardium. In the present study attempt has been made to determine whether oral administration of L-arginine has any effect on oxidant/antioxidant homeostasis in ischemic myocardial patients [represented by the patients of acute angina (AA) and acute myocardial infarction (MI)]. L-arginine has antioxidant and antiapoptotic properties, decreases endothelin-1 expression and improves endothelial function, thereby controlling oxidative injury caused during myocardial ischemic syndrome. Effect of L-arginine administration on the status of free radical scavenging enzymes, pro-oxidant enzyme and antioxidants viz. total thiols, carbonyl content and plasma ascorbic acid levels in the patients has been evaluated. We have observed that L-arginine administration (three grams per day for 15 days) resulted in increased activity of free radical scavenging enzyme superoxide dismutase (SOD) and increase in the levels of total thiols (T-SH) and ascorbic acid with concomitant decrease in lipid per-oxidation, carbonyl content, serum cholesterol and the activity of proxidant enzyme, xanthine oxidase (XO). These findings suggest that the supplementation of L-arginine along with regular therapy may be beneficial to the patients of ischemic myocardial syndromes. PMID:20716909

Nitric oxide signals ROS scavenger-mediated enhancement of PAL activity in nitrogen-deficient Matricaria chamomilla roots: side effects of scavengers.

PubMed

Kovácik, Jozef; Klejdus, Borivoj; Backor, Martin

2009-06-15

Owing to the abundance of phenolic metabolites in plant tissue, their accumulation represents an important tool for stress protection. However, the regulation of phenolic metabolism is still poorly known. The regulatory role of reactive oxygen species (ROS) in the activity of phenylalanine ammonia-lyase (PAL) in nitrogen (N)-deficient chamomile roots treated for 24 h was studied using three ROS scavengers [dithiothreitol (DTT), salicylhydroxamic acid, and sodium benzoate]. Scavengers decreased the level of hydrogen peroxide and/or superoxide (and up-regulated ascorbate/guaiacol peroxidase and glutathione reductase), but, surprisingly, stimulated PAL activity. This up-regulation was correlated with increases in nitric oxide (NO) content, total soluble phenols, selected phenolic acids, and, partially, lignin (being expressed the most in DTT-exposed roots). We therefore tested the hypothesis that NO may be involved in these changes. Application of 2-phenyl-4,4,5,5-tetramethylimidazoline-1-oxyl-3-oxide (PTIO) decreased PAL activity and the accumulation of soluble phenols in all treatments. Exogenous H(2)O(2) and NO also stimulated PAL activity and the accumulation of phenols. We conclude that NO, in addition to hydrogen peroxide, may regulate PAL activity during N deficiency. The anomalous effect of PTIO on NO content and possible mechanism of ROS scavenger-evoked NO increases in light of the current knowledge are also discussed.

Effect of radical scavengers on the inactivation of papain by ascorbic acid in the presence of cupric ions.

PubMed

Kanazawa, H; Fujimoto, S; Ohara, A

1994-04-01

Incubation of papain (EC 3.4.22.2) with ascorbic acid (AsA) and Cu2+ in acetate buffer (pH 5.6) results in an irreversible loss of enzyme activity by site-specific generation of free radicals [H. Kanazawa, S. Fujimoto, A. Ohara, Biol. Pharm.Bull., 16, 11 (1993)]. In this study, the effect of some compounds, known free radical scavengers, on the relationship between the inactivation of papain by the Cu(2+)-AsA system and the oxidation of AsA was investigated. Catalase completely protected the enzyme from inactivation by the Cu(2+)-AsA system, although hydrogen peroxide (H2O2) by itself, known to be generated during the autoxidation of AsA, did not inactivate the enzyme. The oxidation of AsA was unaffected by catalase. Both thiourea and sodium thiocyanate completely protected the enzyme from inactivation, while AsA was partially oxidized only in the initial stage. In the presence of potassium iodide, both the inactivation of the enzyme and the oxidation of AsA were characterized by a rapid initial phase followed by a stable phase where no reaction took place and, subsequently, a slower phase. Histidine partially prevented the inactivation of the enzyme and the oxidation of AsA. The present results suggest that H2O2 serves as a source of secondary, highly reactive species, probably hydroxyl radicals, which are responsible for the inactivation, and that the protection from inactivation by some radical scavengers, such as thiourea, sodium thiocyanate, potassium iodide, and histidine, is based on the removal of metal ions (Cu2+ or Cu+) at the specific site of inactivation.

Metabolic profiling and predicting the free radical scavenging activity of guava (Psidium guajava L.) leaves according to harvest time by 1H-nuclear magnetic resonance spectroscopy.

PubMed

Kim, So-Hyun; Cho, Somi K; Hyun, Sun-Hee; Park, Hae-Eun; Kim, Young-Suk; Choi, Hyung-Kyoon

2011-01-01

Guava leaves were classified and the free radical scavenging activity (FRSA) evaluated according to different harvest times by using the (1)H-NMR-based metabolomic technique. A principal component analysis (PCA) of (1)H-NMR data from the guava leaves provided clear clusters according to the harvesting time. A partial least squares (PLS) analysis indicated a correlation between the metabolic profile and FRSA. FRSA levels of the guava leaves harvested during May and August were high, and those leaves contained higher amounts of 3-hydroxybutyric acid, acetic acid, glutamic acid, asparagine, citric acid, malonic acid, trans-aconitic acid, ascorbic acid, maleic acid, cis-aconitic acid, epicatechin, protocatechuic acid, and xanthine than the leaves harvested during October and December. Epicatechin and protocatechuic acid among those compounds seem to have enhanced FRSA of the guava leaf samples harvested in May and August. A PLS regression model was established to predict guava leaf FRSA at different harvesting times by using a (1)H-NMR data set. The predictability of the PLS model was then tested by internal and external validation. The results of this study indicate that (1)H-NMR-based metabolomic data could usefully characterize guava leaves according to their time of harvesting.

Release of the antioxidants ascorbate and urate from a nitrergically-innervated smooth muscle.

PubMed

Lilley, E; Gibson, A

1997-12-01

1. The main object of the present study was to determine whether ascorbate, an antioxidant which has been shown to protect nitric oxide (NO) from attack by scavenger molecules, might be released from nitrergically-innervated smooth muscle; ascorbate release from the rat anococcygeus was measured by use of h.p.l.c. with electrochemical detection. 2. Incubation of rat anococcygeus muscles in normal physiological salt solution (PSS; 30 min) resulted in release of ascorbate into the bathing medium (7.7 +/- 0.9 nmol g-1 tissue). This release was increased by 96% when muscles were incubated in high K+ (70 mM) PSS. The resting release of ascorbate was unaffected by tetrodotoxin (TTX; 1 microM), omega-conotoxin GVIA (10 nM) or omission of calcium ions from the PSS (with addition of 0.2 mM EGTA), but all three procedures attenuated the increased release observed under depolarizing conditions. Resting release of ascorbate was unaffected by glutamate (100 microM), aspartate (100 microM), gamma-aminobutyric acid (100 microM) or carbachol (50 microM). 3. A second h.p.l.c. peak, which always preceded the ascorbate peak, was identified as urate. Urate release from the anococcygeus, following 30 min incubation in normal PSS, was 64.6 +/- 12.7 nmol g-1 tissue but, unlike ascorbate, urate release was unchanged in high K+ PSS. In functional experiments, urate (100-400 microM) partially protected NO (15 microM)-induced relaxations of the rat anococcygeus from inhibition by 2-(4-carboxyphenyl)-4,4,5,5-tetramethylimidazoline-1-oxyl-3-oxide (carboxy-PTIO; 50 microM), but not from inhibition by hydroquinone or duroquinone (both 100 microM). 4. Muscles chemically sympathectomized with 6-hydroxydopamine (6-OHDA, 500 microM; 2 h) still exhibited release of ascorbate (2.5 +/- 0.4 nmol g-1 tissue) and urate (22.2 +/- 2.9 nmol g-1 tissue); in both cases the release was similar to that observed in time-matched control tissues not exposed to 6-OHDA. High K+ PSS produced a TTX-sensitive increase in release of ascorbate, but not urate, from 6-OHDA-treated muscles. 5. The results demonstrate that significant amounts of ascorbate and urate are released from the rat anococcygeus muscle. Ascorbate, but not urate, release appears to be enhanced by activation of nerves which are resistant to 6-OHDA pretreatment. Since both antioxidants can protect NO from attack by scavenger molecules, their release in nitrergically-innervated tissues may be important for the provision of the correct redox environment to allow NO to fulfill its proposed neurotransmitter role.

Influence of various scavengers of •OH radicals on the radiation sensitivity of yeast and bacteria.

PubMed

Múčka, Viliam; Bláha, Pavel; Čuba, Václav; Červenák, Jaroslav

2013-12-01

To quantitatively investigate the influence of various •OH (hydroxyl radical) scavengers on the radiation sensitivity of yeast and bacteria, particularly to define the relationship between the protective effect of a scavenger and its •OH scavenging efficiency. In order to study the protective effect of •OH scavengers we used various concentrations of four scavengers (methanol, potassium formate, ethanol and ascorbic acid) in isotonic salt solutions. These solutions containing live yeast (Saccharomyces cerevisiae) or bacteria (Escherichia coli) were irradiated with (60)Co isotope γ -radiation using two different doses and dose rates. The number of surviving cells was determined prior to and after irradiation both in suspension with and without scavengers. The surviving fractions after irradiation with and without the scavenger were evaluated. The main results of the paper were: The surviving fraction increased approximately linearly within the measured interval with increasing concentration of the scavenger. The same dependences were found for the protecting effect depending on the scavenging efficiency. The slopes of these dependences (k) were found to be characteristic for each scavenger. The k value determined the degree in which the scavenging of •OH radicals participated in the protection of living cells. The protective effects of scavengers at the same scavenging efficiency were different and unique for each scavenger. No simple relation was found between the efficiency of scavenger k and the rate constant kOH of the reactions between scavengers and •OH radicals. Our results suggest that the studied scavengers effectively protected yeast and bacteria against ionizing radiation. Although the scavenging of •OH radicals seems to be important for protection of living cells, it is clearly not the only process on which the protection is based.

Lipophilization of ascorbic acid: a monolayer study and biological and antileishmanial activities.

PubMed

Kharrat, Nadia; Aissa, Imen; Sghaier, Manel; Bouaziz, Mohamed; Sellami, Mohamed; Laouini, Dhafer; Gargouri, Youssef

2014-09-17

Ascorbyl lipophilic derivatives (Asc-C2 to Asc-C(18:1)) were synthesized in a good yield using lipase from Staphylococcus xylosus produced in our laboratory and immobilized onto silica aerogel. Results showed that esterification had little effect on radical-scavenging capacity of purified ascorbyl esters using DPPH assay in ethanol. However, long chain fatty acid esters displayed higher protection of target lipids from oxidation. Moreover, compared to ascorbic acid, synthesized derivatives exhibited an antibacterial effect. Furthermore, ascorbyl derivatives were evaluated, for the first time, for their antileishmanial effects against visceral (Leishmania infantum) and cutaneous parasites (Leishmania major). Among all the tested compounds, only Asc-C10, Asc-C12, and Asc-C(18:1) exhibited antileishmanial activities. The interaction of ascorbyl esters with a phospholipid monolayer showed that only medium and unsaturated long chain (Asc-C10 to Asc-C(18:1)) derivative esters were found to interact efficiently with mimetic membrane of leishmania. These properties would make ascorbyl derivatives good candidates to be used in cosmetic and pharmaceutical lipophilic formulations.

Adaptogenic and nootropic activities of aqueous extract of Vitis vinifera (grape seed): an experimental study in rat model

PubMed Central

Sreemantula, Satyanarayana; Nammi, Srinivas; Kolanukonda, Rajabhanu; Koppula, Sushruta; Boini, Krishna M

2005-01-01

Background The aerial parts of Vitis vinifera (common grape or European grape) have been widely used in Ayurveda to treat a variety of common and stress related disorders. In the present investigation, the seed extract of V. vinifera was evaluated for antistress activity in normal and stress induced rats. Furthermore, the extract was studied for nootropic activity in rats and in-vitro antioxidant potential to correlate its antistress activity. Methods For the evaluation of antistress activity, groups of rats (n = 6) were subjected to forced swim stress one hour after daily treatment of V. vinifera extract. Urinary vanillylmandelic acid (VMA) and ascorbic acid were selected as non-invasive biomarkers to assess the antistress activity. The 24 h urinary excretion of vanillylmandelic acid (VMA) and ascorbic acid were determined by spectrophotometric methods in all groups under normal and stressed conditions. The nootropic activity of the extract as determined from acquisition, retention and retrieval in rats was studied by conditioned avoidance response using Cook's pole climbing apparatus. The in vitro antioxidant activity was determined based on the ability of V. vinifera to scavenge hydroxyl radicals. Results Daily administration of V. vinifera at doses of 100, 200 and 300 mg/kg body weight one hour prior to induction of stress inhibited the stress induced urinary biochemical changes in a dose dependent manner. However, no change in the urinary excretion of VMA and ascorbic acid was observed in normal animals at all the doses studied. The cognition, as determined by the acquisition, retention and recovery in rats was observed to be dose dependent. The extract also produced significant inhibition of hydroxyl radicals in comparison to ascorbic acid in a dose dependent manner. Conclusion The present study provides scientific support for the antistress (adaptogenic), antioxidant and nootropic activities of V. vinifera seed extract and substantiate the traditional claims for the usage of grape fruits and seeds in stress induced disorders. PMID:15656916

One-step green route to narrowly dispersed copper nanocrystals

NASA Astrophysics Data System (ADS)

Wu, Chunwei; Mosher, Brian P.; Zeng, Taofang

2006-12-01

We report a total "green" chemical method in aqueous solution for synthesizing stable narrowly distributed copper nanoparticles with average diameter less than 5 nm in the presence of Polyvinylpyrrolidone (PVP) as a stabilizer and without any inert gas protection. In our synthesis route, ascorbic acid, natural vitamin C (VC), an excellent oxygen scavenger, acts as both reducing agent and antioxidant, to reduce the metallic ion precursor, and to effectively prevent the common oxidation process of the newborn pure copper nanoclusters.

Alleviation of ascorbic acid-induced gastric high acidity by calcium ascorbate in vitro and in vivo.

PubMed

Lee, Joon-Kyung; Jung, Sang-Hyuk; Lee, Sang-Eun; Han, Joo-Hui; Jo, Eunji; Park, Hyun-Soo; Heo, Kyung-Sun; Kim, Deasun; Park, Jeong-Sook; Myung, Chang-Seon

2018-01-01

Ascorbic acid is one of the most well-known nutritional supplement and antioxidant found in fruits and vegetables. Calcium ascorbate has been developed to mitigate the gastric irritation caused by the acidity of ascorbic acid. The aim of this study was to compare calcium ascorbate and ascorbic acid, focusing on their antioxidant activity and effects on gastric juice pH, total acid output, and pepsin secretion in an in vivo rat model, as well as pharmacokinetic parameters. Calcium ascorbate and ascorbic acid had similar antioxidant activity. However, the gastric fluid pH was increased by calcium ascorbate, whereas total acid output was increased by ascorbic acid. In the rat pylorus ligation-induced ulcer model, calcium ascorbate increased the gastric fluid pH without changing the total acid output. Administration of calcium ascorbate to rats given a single oral dose of 100 mg/kg as ascorbic acid resulted in higher plasma concentrations than that from ascorbic acid alone. The area under the curve (AUC) values of calcium ascorbate were 1.5-fold higher than those of ascorbic acid, and the C max value of calcium ascorbate (91.0 ng/ml) was higher than that of ascorbic acid (74.8 ng/ml). However, their T max values were similar. Thus, although calcium ascorbate showed equivalent antioxidant activity to ascorbic acid, it could attenuate the gastric high acidity caused by ascorbic acid, making it suitable for consideration of use to improve the side effects of ascorbic acid. Furthermore, calcium ascorbate could be an appropriate antioxidant substrate, with increased oral bioavailability, for patients with gastrointestinal disorders.

Alleviation of ascorbic acid-induced gastric high acidity by calcium ascorbate in vitro and in vivo

PubMed Central

Lee, Joon-Kyung; Jung, Sang-Hyuk; Lee, Sang-Eun; Han, Joo-Hui; Jo, Eunji; Park, Hyun-Soo; Heo, Kyung-Sun; Kim, Deasun

2018-01-01

Ascorbic acid is one of the most well-known nutritional supplement and antioxidant found in fruits and vegetables. Calcium ascorbate has been developed to mitigate the gastric irritation caused by the acidity of ascorbic acid. The aim of this study was to compare calcium ascorbate and ascorbic acid, focusing on their antioxidant activity and effects on gastric juice pH, total acid output, and pepsin secretion in an in vivo rat model, as well as pharmacokinetic parameters. Calcium ascorbate and ascorbic acid had similar antioxidant activity. However, the gastric fluid pH was increased by calcium ascorbate, whereas total acid output was increased by ascorbic acid. In the rat pylorus ligation-induced ulcer model, calcium ascorbate increased the gastric fluid pH without changing the total acid output. Administration of calcium ascorbate to rats given a single oral dose of 100 mg/kg as ascorbic acid resulted in higher plasma concentrations than that from ascorbic acid alone. The area under the curve (AUC) values of calcium ascorbate were 1.5-fold higher than those of ascorbic acid, and the Cmax value of calcium ascorbate (91.0 ng/ml) was higher than that of ascorbic acid (74.8 ng/ml). However, their Tmax values were similar. Thus, although calcium ascorbate showed equivalent antioxidant activity to ascorbic acid, it could attenuate the gastric high acidity caused by ascorbic acid, making it suitable for consideration of use to improve the side effects of ascorbic acid. Furthermore, calcium ascorbate could be an appropriate antioxidant substrate, with increased oral bioavailability, for patients with gastrointestinal disorders. PMID:29302210

Chemical composition, iron bioavailability, and antioxidant activity of Kappaphycus alvarezzi (Doty).

PubMed

Fayaz, Mohamed; Namitha, K K; Murthy, K N Chidambara; Swamy, M Mahadeva; Sarada, R; Khanam, Salma; Subbarao, P V; Ravishankar, G A

2005-02-09

Kappaphycus alvarezzi, an edible seaweed from the west coast of India, was analyzed for its chemical composition. It was found that K. alvarezzi is rich in protein (16.24% w/w) and contains a high amount of fiber (29.40% w/w) and carbohydrates (27.4% w/w). K. alvarezzi showed vitamin A activity of 865 mug retinal equivalents/100 g of sample. It contained a higher quantity of unsaturated fatty acids (44.50% of the total), in which relative percentage of oleic acid was 11%, cis-heptadecanoic acid 13.50%, and linoleic acid 2.3% and 37.0% of saturated fatty acids (mainly heptadecanoic acid). K. alvarezziwas also found to be good source of minerals, viz 0.16% of calcium, 0.033% of iron, and 0.016% of zinc, which are essential for various vital biological activities. Bioavailability of iron by in vitro methods showed a higher efficiency in intestinal conditions than in stomach conditions. Ascorbic acid influenced higher bioavailability of iron. Successive extracts of n-hexane, acetone, ethyl acetate, ethanol, and direct extractables of chloroform/methanol (1:1 and 2:1) were screened for antioxidant activity using a beta-carotene linoleic acid model system (B-CLAMS), DPPH (alpha,alpha-diphenyl-beta-picrylhydrazyl) model system and hydroxyl radical scavenging activity. The chloroform/methanol (2:1) extract has shown 82.5% scavenging activity at 1000 ppm. Acetone fraction extracts at the 1000 ppm level showed 63.31% antioxidant activity in beta-carotene linoleic acid system. The acetone extract showed 46.04% scavenging activity at 1000 ppm concentration. In the case of hydroxyl radical scavenging activity, all the extracts showed better activity at the concentrations of 25 and 50 ppm, where at the 50 ppm level ethyl acetate extract showed 76.0%, acetone 75.12%, and hexane 71.15% activity, respectively. Results of this study suggest the utility of K. alvarezzi (Eucheuma) for various nutritional products, including antioxidant for use as health food or nutraceutical supplement.

Scavenger and antioxidant properties of prenylflavones isolated from Artocarpus heterophyllus.

PubMed

Ko, F N; Cheng, Z J; Lin, C N; Teng, C M

1998-07-15

The antioxidant properties of prenylflavones, isolated from Artocarpus heterophyllus Lam., was evaluated in this study. Among them, artocarpine, artocarpetin, artocarpetin A, and cycloheterophyllin diacetate and peracetate had no effect on iron-induced lipid peroxidation in rat brain homogenate. They also did not scavenge the stable free radical 1,1-diphenyl-2-picrylhydrazyl. In contrast, cycloheterophyllin and artonins A and B inhibited iron-induced lipid peroxidation in rat brain homogenate and scavenged 1,1-diphenyl-2-picrylhydrazyl. They also scavenged peroxyl radicals and hydroxyl radicals that were generated by 2,2'-azobis(2-amidinopropane) dihydrochloride and the Fe3+-ascorbate-EDTA-H2O2 system, respectively. However, they did not inhibit xanthine oxidase activity or scavenge superoxide anion, hydrogen peroxide, carbon radical, or peroxyl radicals derived from 2,2'-azobis(2,4-dimethylvaleronitrile) in hexane. Moreover, cycloheterophyllin and artonins A and B inhibited copper-catalyzed oxidation of human low-density lipoprotein, as measured by fluorescence intensity, thiobarbituric acid-reactive substance and conjugated-diene formations and electrophoretic mobility. It is concluded that cycloheterophyllin and artonins A and B serve as powerful antioxidants against lipid peroxidation when biomembranes are exposed to oxygen radicals.

Changes in phytochemical and antioxidant activity of selected pepper cultivars (Capsicum species) as influenced by maturity.

PubMed

Howard, L R; Talcott, S T; Brenes, C H; Villalon, B

2000-05-01

The effect of fruit maturation on changes in carotenoids, flavonoids, total soluble reducing equivalents, phenolic acids, ascorbic acid, and antioxidant activity (AOX) in different pepper types (Capsicum annuum, Capsicum frutescens, and Capsicum chinese) was determined. Generally, the concentration of these chemical constituents increased as the peppers reached maturity. Peppers contained high levels of L-ascorbic acid and carotenoids at maturity, contributing 124-338% of the RDA for vitamin C and 0.33-336 RE/100 g of provitamin A activity, respectively. Levels of phenolic acids, capxanthin, and zeaxanthin generally increased during maturation, whereas the level of lutein declined. Flavonoid concentrations varied greatly among the pepper types analyzed and were negatively correlated to AOX under the conditions of the beta-carotene-linoleic assay. Model systems were used to aid in understanding the relationship between flavonoids and AOX. Significant increases in AOX were observed in pepper juice models in response to increasing dilution factors and the presence of EDTA, indicating a pro-oxidant effect due to metal ions in the system. In vitro models demonstrated that increasing levels of flavonoids in combination with constant levels of caffeic and ascorbic acid gave a resultant AOX that was either additive of the two compounds or competitive in their ability to scavenge peroxyl radicals. The model systems were in good agreement with the chemical composition of the pepper cultivars and reflected the interactions affecting AOX. More research is needed to understand the complex interactions that occur among various antioxidants present in pepper extracts.

Effects of P25 TiO2 Nanoparticles on the Free Radical-Scavenging Ability of Antioxidants upon Their Exposure to Simulated Sunlight.

PubMed

Li, Meng; Chong, Yu; Fu, Peter P; Xia, Qingsu; Croley, Timothy R; Lo, Y Martin; Yin, Jun-Jie

2017-11-15

Although nanosized ingredients, including TiO 2 nanoparticles (NPs), can be found in a wide range of consumer products, little is known about the effects these particles have on other active compounds in product matrices. These NPs can interact with reactive oxygen species (ROS), potentially disrupting or canceling the benefits expected from antioxidants. We used electron spin resonance spectrometry to assess changes in the antioxidant capacities of six dietary antioxidants (ascorbic acid, α-tocopherol, glutathione, cysteine, epicatechin, and epicatechin gallate) during exposure to P25 TiO 2 and/or simulated sunlight. Specifically, we determined the ability of these antioxidants to scavenge 1-diphenyl-2-picryl-hydrazyl radical, superoxide radical, and hydroxyl radical. Exposure to simulated sunlight alone did not lead to noticeable changes in radical-scavenging abilities; however, in combination with P25 TiO 2 NPs, the scavenging abilities of most antioxidants were weakened. We found glutathione to be the most resistant to treatment with sunlight and NPs among these six antioxidants.

Preliminary assessment of free radical scavenging, thrombolytic and membrane stabilizing capabilities of organic fractions of Callistemon citrinus (Curtis.) skeels leaves.

PubMed

Ahmed, Farhana; Rahman, Mohammad Sharifur

2016-07-26

Callistemon citrinus (Curtis.) (Family- Myrtaceae) is a popular evergreen shrub in Bangladesh. In the present study, the leaves of this plant have been assessed comprehensively for free radical scavenging, thrombolytic and membrane stabilizing activities. The leaves were collected, powdered and extracted with methanol. The extract was then concentrated and successively fractionated into petroleum ether, carbon tetrachloride, chloroform and aqueous soluble fractions. The extractives were investigated for free radical scavenging, thrombolytic and membrane stabilizing activities. In case of 1,1 diphenyl-2-picrylhydrazyl (DPPH) and hydrogen peroxide radical scavenging assays, the crude methanol extract of the leaves showed the highest free radical scavenging activity among the tested materials including standard ascorbic acid (p = 0.0000). Besides, this extract was also found significantly rich (p = 0.0000) in phenolics and flavonoids compared to other organic fractions. In thrombolytic study, the petroleum ether fraction exhibited significantly stronger thrombolysis (p = 0.024) than other leaf extractives but was weaker than the standard streptokinase. In membrane stabilizing assay, the activity of chloroform fraction was similar to that of standard acetylsalicylic acid (p = 1.000) in hypotonic solution induced hemolysis. However, membrane stabilization activity of this chloroform fraction was found significantly stronger than that of the standard (p = 0.0000) in heat induced hemolysis. This study has revealed the medicinal capabilities of different organic fractions of C. citrinus displaying free radical scavenging, thrombolysis and membrane stabilizing antiinflammatory potentials. Further bioactivity guided isolation is required to obtain pharmacologically secondary metabolites.

Role of Auxin-Induced Reactive Oxygen Species in Root Gravitropism1

PubMed Central

Joo, Jung Hee; Bae, Yun Soo; Lee, June Seung

2001-01-01

We report our studies on root gravitropism indicating that reactive oxygen species (ROS) may function as a downstream component in auxin-mediated signal transduction. A transient increase in the intracellular concentration of ROS in the convex endodermis resulted from either gravistimulation or unilateral application of auxin to vertical roots. Root bending was also brought about by unilateral application of ROS to vertical roots pretreated with the auxin transport inhibitor N-1-naphthylphthalamic acid. Furthermore, the scavenging of ROS by antioxidants (N-acetylcysteine, ascorbic acid, and Trolox) inhibited root gravitropism. These results indicate that the generation of ROS plays a role in root gravitropism. PMID:11457956

Selection of the best active modified atmosphere packaging with ethylene and moisture scavengers to maintain quality of guava during low-temperature storage.

PubMed

Murmu, Sanchita Biswas; Mishra, Hari Niwas

2018-07-01

In modified atmosphere packaging of guava, moisture scavenger (MS) sachet containing 30-50 g of coarse silica gel and ethylene scavenger (ES) sachet containing 0-4 g of potassium permanganate was added as per central composite rotatable design. The headspace O 2 and CO 2 of the packages were studied at 4, 8 and 12 °C for 30 days and thereafter the guava were left for two days to ripen at 30 °C. After that the chilling injuries, percentage acceptable guava, peel color and pulp texture was analyzed. After two days ripening at 30 °C the samples with 3 g ES and 46 g MS registered higher L ∗ , lower a ∗ value & firmness (16.65 N), lowest chilling injury score. About 95% of guava was found acceptable in this treatment with 1.89-2.79% reducing sugar, 0.95-1.1% titrable acidity, 59% and 46.61% retention of total phenols and ascorbic acid respectively, resulting 32 days shelf-life of guava. Copyright © 2018 Elsevier Ltd. All rights reserved.

Proximate Composition and Antioxidant Potential of Leaves from Three Varieties of Mulberry (Morus sp.): A Comparative Study

PubMed Central

Iqbal, Shahid; Younas, Umer; Sirajuddin; Chan, Kim Wei; Sarfraz, Raja Adil; Uddin, Kamal

2012-01-01

In this study, leaves of three indigenous varieties of Mulberry namely, Morus alba L., Morus nigra L. and Morus rubra L. were investigated for their antioxidant potential and their proximate composition was determined. The yields of 80% methanolic extracts ranged between 8.28–13.89%. The contents of total phenolics (TPC), total flavonoids (TFC) and ascorbic acid (AA) ranged between 16.21–24.37 mg gallic acid equivalent (GAE)/g, 26.41–31.28 mg rutin equivalent (RE)/g and 0.97–1.49 mg/g, respectively. The antioxidant activity of leaf extracts was evaluated by measuring 1,1-diphenyl-2-picrylhydrazyl (DPPH•) radical scavenging actity, 2,2′-azino-bis-(3-ethylbenzthiazoline-6-sulphonic acid (ABTS•+) radical cation scavenging capacity and ferric ion reducing power and values ranged between 1.89–2.12, 6.12–9.89 and 0.56–0.97 mM Trolox equivalent/g of dried leaves, respectively. The investigated features reveal good nutritive and antioxidant attributes of all the varieties with mutually significant differences. PMID:22837655

Antioxidant Compounds in Traditional Indian Pickles May Prevent the Process-Induced Formation of Benzene.

PubMed

Kharat, Mahesh M; Adiani, Vanshika; Variyar, Prasad; Sharma, Arun; Singhal, Rekha S

2016-01-01

Pickles in the Indian market contain ascorbic acid from the raw material used and benzoate as an added preservative that are involved in the formation of benzene in soft drinks. In this work, 24 market pickle samples were surveyed for benzene content, as well as its precursors and other constituents that influence its formation. The analysis showed that pickle samples were high in acid content (low pH) and showed significant amount of ascorbic acid, minerals (Cu and Fe), and benzoic acid present in them. Also, most samples exhibited high antioxidant activity that might be attributed to the ingredients used, such as fruits and spices. The solid-phase microextraction headspace gas chromatography-mass spectrometry method was developed in-house for benzene analysis. Eleven of 24 samples had benzene, with the highest concentration of 4.36 ± 0.82 μg of benzene per kg of pickle for a lime pickle that was also reported to have highest benzoic acid and considerably less hydroxyl radical ((•)OH) scavenging activity. However, benzene levels for all 11 samples were considerably below the World Health Organization regulatory limit of 10 μg/kg for benzene in mineral water. Studies on model systems revealed that the high antioxidant activity of Indian pickles may have had a strong inhibitory effect on benzene formation.

Antioxidant and hepatoprotective activity of Cordia macleodii leaves

PubMed Central

Qureshi, Naseem N.; Kuchekar, Bhanudansh S.; Logade, Nadeem A.; Haleem, Majid A.

2009-01-01

This investigation was undertaken to evaluate ethanolic extract of Cordia macleodii leaves for possible antioxidant and hepatoprotective potential. Antioxidant activity of the extracts was evaluated by four established, in vitro methods viz. 1,1-diphenyl-2-picryl hydrazyl (DPPH) radical scavenging method, nitric oxide (NO) radical scavenging method, iron chelation method and reducing power method. The extract demonstrated a significant dose dependent antioxidant activity comparable with ascorbic acid. The extract was also evaluated for hepatoprotective activity by carbon tetrachloride (CCl4) induced liver damage model in rats. CCl4 produced a significant increase in levels of serum glutamate pyruvate transaminase (GPT), serum glutamate oxaloacetate transaminase (GOT), Alkaline Phosphatase (ALP) and total bilirubin. Pretreatment of the rats with ethanolic extract of C. macleodii (100, 200 and 400 mg/kg po) inhibited the increase in levels of GPT, GOT, ALP and total bilirubin and the inhibition was comparable with Silymarin (100 mg/kg po). The present study revealed that C. macleodii leaves have significant radical scavenging and hepatoprotective activities. PMID:23960714

Role of Vitamin C in the Function of the Vascular Endothelium

PubMed Central

Harrison, Fiona E.

2013-01-01

Abstract Significance: Vitamin C, or ascorbic acid, has long been known to participate in several important functions in the vascular bed in support of endothelial cells. These functions include increasing the synthesis and deposition of type IV collagen in the basement membrane, stimulating endothelial proliferation, inhibiting apoptosis, scavenging radical species, and sparing endothelial cell-derived nitric oxide to help modulate blood flow. Although ascorbate may not be able to reverse inflammatory vascular diseases such as atherosclerosis, it may well play a role in preventing the endothelial dysfunction that is the earliest sign of many such diseases. Recent Advances: Beyond simply preventing scurvy, evidence is mounting that ascorbate is required for optimal function of many dioxygenase enzymes in addition to those involved in collagen synthesis. Several of these enzymes regulate the transcription of proteins involved in endothelial function, proliferation, and survival, including hypoxia-inducible factor-1α and histone and DNA demethylases. More recently, ascorbate has been found to acutely tighten the endothelial permeability barrier and, thus, may modulate access of ascorbate and other molecules into tissues and organs. Critical Issues: The issue of the optimal cellular content of ascorbate remains unresolved, but it appears that low millimolar ascorbate concentrations are normal in most animal tissues, in human leukocytes, and probably in the endothelium. Although there may be little benefit of increasing near maximal cellular ascorbate concentrations in normal people, many diseases and conditions have either systemic or localized cellular ascorbate deficiency as a cause for endothelial dysfunction, including early atherosclerosis, sepsis, smoking, and diabetes. Future Directions: A key focus for future studies of ascorbate and the vascular endothelium will likely be to determine the mechanisms and clinical relevance of ascorbate effects on endothelial function, permeability, and survival in diseases that cause endothelial dysfunction. Antioxid. Redox Signal. 19, 2068–2083. PMID:23581713

Effect on Tumor Necrosis Factor-α Production and Antioxidant Ability of Black Alder, as Factors Related to Its Anti-Inflammatory Properties

PubMed Central

Acero, Nuria

2012-01-01

Abstract Alders exhibit several uses in different areas and also offer some nutritional and medicinal values. The bark and leaves from black alder [Alnus glutinosa (L.) Gaertn] are used in folk medicine for the treatment of inflammatory processes and other health disorders. This study assessed if an extract of A. glutinosa stem bark exhibits some biological properties linked to improving the inflammatory state, which could partly justify its ethnopharmacological use. Therefore, various aspects of antioxidant activity as well as the effect on tumor necrosis factor-α (TNF-α) production were evaluated. The phytochemical study revealed the presence of terpenes, saponins, tannins, flavonoids, and anthraquinones (by high-performance thin-layer chromatography). The betulinic acid content in the extract, determined by reversed-phase high-performance liquid chromatography (validated method), was 0.72±0.027%. In addition, high amounts for total phenols as well as flavonoids were determined. The extract exhibited a 2,2′-diphenylpicrylhydrazyl radical scavenging capacity similar to that of ascorbic acid and had a significant effect on superoxide anion scavenging, superior to that of ascorbic acid. It was also able to protect HeLa cells from induced oxidative stress. In the TNF-α assay, levels of this citokine were depressed by the extract in HL-60 cells. To test the effect of the extract on cell proliferation, a 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay was performed. According to the results, the antioxidant properties displayed by the extract of A. glutinosa stem bark, together with the effect on TNF-α levels, suggest that these activities, linked to a successful reduction in inflammatory processes, may support, in part, its ethnopharmacological use. PMID:22424456

HPLC profiling, antioxidant and in vivo anti-inflammatory activity of the ethanol extract of Syzygium jambos available in Bangladesh.

PubMed

Hossain, Hemayet; Rahman, Shaikh Emdadur; Akbar, Proity Nayeeb; Khan, Tanzir Ahmed; Rahman, Md Mahfuzur; Jahan, Ismet Ara

2016-03-28

Syzygium jambos has been used as a traditional medicine for the treatment of inflammatory diseases in Bangladesh. The study investigates the high performance liquid chromatography (HPLC) profiling of phenolic compounds, and evaluates the antioxidant and anti-inflammatory activities of ethanol extract of S. jambos available in Bangladesh. The extract was subjected to HPLC for the identification and quantification of the major bioactive polyphenols present in S. jambos. Antioxidant activity was determined using 2, 2'-azino bis-3-ethylbenzothiazoline-6-sulfonic acid (ABTS) radical scavenging, reducing power assay, total antioxidant capacity, total phenolic and flavonoid content. Furthermore, the anti-inflammatory effect of the extract in rats for two different test models: carrageenan and histamine-induced paw edema was inspected. High levels of catechin hydrate and rutin hydrate (99.00 and 79.20 mg/100 g extract, respectively) and moderate amounts of ellagic acid and quercetin (59.40 and 69.30 mg/100 g extract, respectively) were quantified in HPLC. Catechin hydrate from this plant extract was determined for the first time through HPLC. For ABTS scavenging assay, the median inhibition concentration (IC50) value of S. jambos was 57.80 µg/ml, which was significant to that of ascorbic acid (12.01 µg/ml). The maximum absorbance for reducing power assay was found to be 0.4934. The total antioxidant capacity, phenolic and flavonoid contents were calculated to be 628.50 mg/g of ascorbic acid, 230.82 mg/g of gallic acid and 11.84 mg/g of quercetin equivalent, respectively. At a dose of 400 mg/kg, a significant acute anti-inflammatory activity (P < 0.01) was observed in rats for both the test models with a reduction in the paw volume of 58.04 and 53.95 %, in comparison to those of indomethacin (62.94 and 65.79 %), respectively. The results suggest that the phenolic and flavonoid compounds are responsible for acute anti-inflammatory and antioxidant activities of S. jambos.

The protective effects of ascorbic acid, cimetidine, and nifedipine on diethyldithiocarbamate-induced hepatic toxicity in albino rats.

PubMed

Gaafa, Khadiga Mohammed; Badawy, Mohammed M; Hamza, Alaaeldin A

2011-10-01

The aim of the present work was to clarify the involvement of free radicals, cytochrome P450 toxic metabolites, and deregulation of calcium homeostasis in the mechanism of diethyldithiocarbamate (DDC) hepatotoxicity. This was elucidated through the preadministration of ascorbic acid (a free radical scavenger), cimetidine (an inhibitor of cytochrome P450 enzymes), or nifedipine (a calcium-blocking agent) before DDC treatment to male albino rats. DDC was administered either as a single dose [800 mg/kg body weight (b.w.), subcutaneously, s.c.] or daily repeated doses for 30 days (400 mg/kg b.w., s.c.). Oxidative stress indicators [e.g., malondialdehyde (MDA), reduced glutathione (GSH), and superoxide dismutase enzyme (SOD)] showed that single or repeated DDC doses induce an increase in MDA level and a decrease in SOD activity in the liver, whereas it causes depletion in hepatic GSH after a single dose and an elevation in its value after repeated doses. Severe histopathological changes were also observed in the livers of rats treated with single or repeated DDC doses. Ascorbic acid, cimetidine, and nifedipine pretreatments were found to induce highly protective effects against the evinced DDC hepatotoxicity, manifesting that free radical, cytochrome P450, and calcium-dependent processes contribute to DDC liver toxicity. Finally, although multiple mechanisms may be involved in the hepatotoxic changes induced by DDC, calcium disarrangement and free radical formation play a more critical role than cytochrome P450 in metabolic events leading to toxic effects of DDC.

Trypsin Inhibitors from Cajanus cajan and Phaseolus limensis Possess Antioxidant, Anti-Inflammatory, and Antibacterial Activity.

PubMed

Shamsi, Tooba Naz; Parveen, Romana; Afreen, Sumbul; Azam, Mudasser; Sen, Priyankar; Sharma, Yamini; Haque, Qazi Mohd Rizwanul; Fatma, Tasneem; Manzoor, Nikhat; Fatima, Sadaf

2018-01-18

Protease inhibitors are one of the most promising and investigated subjects for their role in pharmacognostic and pharmacological studies. This study aimed to investigate antioxidant, anti-inflammatory, and antimicrobial activities of trypsin inhibitors (TIs) from two plant sources (Cajanus cajan and Phaseolus limensis). TI was purified from C. cajan (PUSA-992) by ammonium sulfate precipitation followed by ion exchange chromatography. TI from Phaseolus limensis (lima bean trypsin inhibitor; LBTI) was procured from Sigma-Aldrich, St. Louis, Missouri, United States. The antioxidant activity was analyzed by ferric ion reducing antioxidant power (FRAP) and 2,2-diphenyl-1-picrylhydrazyl (DPPH). The anti-inflammatory property of TIs was determined by inhibition of albumin denaturation assay. Ascorbic acid and aspirin were used as standards for antioxidant and anti-inflammatory assays, respectively. These TIs were tested against various bacterial and fungal strains. The TIs showed DPPH radical-scavenging activity in a concentration-dependent manner with IC 50 values comparable to ascorbic acid. The FRAP values were also observed comparable to ascorbic acid and followed the trend of dose-dependent manner. The half maximal inhibitory concentration (IC 50 ) values of CCTI and LBTI in anti-inflammatory test showed that LBTI is more potent than CCTI. The TIs showed potent antibacterial activity, but apparently no action against fungi. This study has reported the biological properties of CCTI and LBTI for the first time. The results show that TIs possess the ability to inhibit diseases caused by oxidative stress, inflammation, and bacterial infestation.

Comparative assessment on in vitro antioxidant activities of ethanol extracts of Averrhoa bilimbi, Gymnema sylvestre and Capsicum frutescens.

PubMed

Rahman, Md Mominur; Habib, Md Razibul; Hasan, Md Anayet; Al Amin, Mohammad; Saha, Ayan; Mannan, Adnan

2014-01-01

Averrhoa bilimbi, Gymnema sylvestre and Capsicum frutescens are medicinal plants commonly used as traditional medicine for the treatment of various diseases. The present study was designed to investigate the antioxidant activities of Ethanolic extract of A. bilimbi, G. sylvestre and C. frutescens. The antioxidant activity of the extracts were evaluated using total phenolic and flavonoid contents, ferric reducing power and the free radical scavenging activity against 1,1-diphenyl-2-picrylhydrazyl (DPPH). Total phenolic and flavonoid contents were higher in G. sylvestre (53.63636 ± 0.454545 mg/g gallic acid equivalent) and C. frutescens (26.66667 ± 2.081666 mg/g quercetin equivalent) respectively. Reducing power of the crude ethanol extracts increased with the concentrations of the extracts and all the extracts showed moderate free radical scavenging activity against DPPH. The plant extract displayed moderate phenolic and flavonoid contents compared to gallic acid and quercetin equivalent respectively, whereas also exhibited significant scavenging of DPPH radical and reducing power compared with ascorbic acid as standard. Our study suggests that G. sylvestre has significant antioxidant activity. The antioxidant compound of this plant might be a therapeutic candidate against oxidative stress related diseases. Different sub-fraction of A. bilimbi and C. frutescens should be studied further to assess the effect. Further study is necessary for isolation and characterization of the active antioxidant agents for better treatment.

Studies on chemical constituents and bioactivity of Rosa micrantha: an alternative antioxidants source for food, pharmaceutical, or cosmetic applications.

PubMed

Guimarães, Rafaela; Barros, Lillian; Carvalho, Ana Maria; Ferreira, Isabel C F R

2010-05-26

Rose species have long been used for food and medicinal purposes. Rosa micrantha is one of the rose species that grow feral in the northeastern Portuguese region so-called Nordeste Transmontano. For the first time, chemical composition and bioactivity of their petals, fertilized flowers, unripe, ripening, and overripe hips were evaluated in order to valorize them as sources of important phytochemicals. Chemical characterization included determination of proteins, fats, ash, and carbohydrates, particularly sugars, by HPLC-RI, fatty acids by GC-FID, tocopherols by HPLC-fluorescence, and phenolics, flavonoids, carotenoids, and ascorbic acid by spectrophotometric techniques. Bioactivity was evaluated through screening of antioxidant properties: radical scavenging effects, reducing power, and inhibition of lipid peroxidation. Ripening and overripe hips showed high nutritional value including proteins, carbohydrates, omega-3 and omega-6 fatty acids, energy, sugars, particularly the reducing sugars fructose and glucose, and ascorbic acid (>693 mg/100 g). Fertilized flowers and petals revealed the highest antioxidant activity (EC(50) > 152 microg/mL) and phenolics, flavonoids, and tocopherols contents (>35 mg/100 g). Furthermore, petals, ripening, and overripe hips are important sources of carotenoid pigments (>64 mg/100 g). Because of the diversity and abundance of antioxidants found in this species, some food, cosmetic, and pharmaceutical applications could be explored.

Chemical constituents and their acetyl cholinesterase inhibitory and antioxidant activities from leaves of Acanthopanax henryi: potential complementary source against Alzheimer's disease.

PubMed

Zhang, Xiao Dan; Liu, Xiang Qian; Kim, Yang Hee; Whang, Wan Kyunn

2014-05-01

The aim of this study was to investigate chemical constituents of the leaves of Acanthopanax henryi, and their antioxidant, acetyl cholinesterase inhibitory activities. Caffeoyl quinic acid derivates and flavonoids were obtained from A. henry, through column chromatography technologies, and the content of major constituents was determined by the HPLC-UV method. Anti-oxidant activity of the isolated metabolites was evaluated by free radical scavenging (DPPH, ABTS radicals) and superoxide anion scavenging. The results showed that di-caffeoyl quinic acid derivates had stronger antioxidant activity than positive controls (ascorbic acid, trolox and allopurinol). Acetyl cholinesterase inhibitory activity was estimated on the constituents, among which, quercetin, 4-caffeoyl-quinic acid and 4,5-caffeoyl quinic acid were found to have strong acetyl cholinesterase inhibitory activity with IC50 values ranging from 62.6 to 121.9 μM. The present study showed that some of the tested constituents from the leaves of A. henryi exhibit strong antioxidant and acetyl cholinesterase inhibitory effects. This suggest that the leaves of A. henryi can be used as a new natural complementary source of acetyl cholinesterase inhibitors and anti-oxidant agents, thus being a promising potential complementary source against Alzheimer's disease.

Synergistic protective role of mirazid (Commiphora molmol) and ascorbic acid against tilmicosin-induced cardiotoxicity in mice.

PubMed

Abdel-Daim, Mohamed M; Ghazy, Emad W; Fayez, Mostafa

2015-01-01

Tilmicosin (TIL) is a long-acting macrolide antibiotic approved for the treatment of cattle with Bovine Respiratory Disease. However, overdose of TIL has been reported to induce cardiotoxicity. The purpose of our experiment was to evaluate the protective effects of Commiphora molmol (mirazid (MRZ); myrrh) and (or) ascorbic acid (AA) against TIL-induced cardiotoxicity in mice. MRZ and AA were orally administered using stomach gavage, either alone or in combination for 5 consecutive days, followed with a single TIL overdose. TIL overdose induced a significant increase in serum levels of cardiac damage biomarkers (AST, LDH, CK, CK-MB, and cTnT), as well as cardiac lipid peroxidation, but cardiac levels of antioxidant biomarkers (GSH, SOD, CAT, and TAC) were decreased. Both MRZ and AA tended to normalize the elevated serum levels of cardiac injury biomarkers. Furthermore, MRZ and AA reduced TIL-induced lipid peroxidation and oxidative stress parameters. MRZ and AA combined produced a synergistic cardioprotective effect. We conclude that myrrh and (or) vitamin C administration minimizes the toxic effects of TIL through their free-radical-scavenging and potent antioxidant activities.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ames, B.N.; Cathcart, R.; Schwiers, E.

During primate evolution, a major factor in lengthening life-span and decreasing age-specific cancer rates may have been improved protective mechanisms against oxygen radicals. We propose that one of these protective systems is plasma uric acid, the level of which increased markedly during primate evolution as a consequence of a series of mutations. Uric acid is a powerful antioxidant and is a scavenger of singlet oxygen and radicals. We show that, at physiological concentrations, urate reduces the oxo-heme oxidant formed by peroxide reaction with hemoglobin, protects erythrocyte ghosts against lipid peroxidation, and protects erythrocytes from peroxidative damage leading to lysis. Uratemore » is about as effective an antioxidant as ascorbate in these experiments. Urate is much more easily oxidized than deoxynucleosides by singlet oxygen and is destroyed by hydroxyl radicals at a comparable rate. The plasma urate level in humans (about 300 ..mu..M) is considerably higher than the ascorbate level, making it one of the major antioxidants in humans. Previous work on urate reported in the literature supports our experiments and interpretations, although the findings were not discussed in a physiological context.« less

Anti-inflammatory, cyclooxygenase (COX)-2, COX-1 inhibitory, and free radical scavenging effects of Rumex nepalensis.

PubMed

Gautam, Raju; Karkhile, Kailas V; Bhutani, Kamlesh K; Jachak, Sanjay M

2010-10-01

Evaluation of the topical anti-inflammatory activity of chloroform and ethyl acetate extracts of RUMEX NEPALENSIS roots in a TPA-induced acute inflammation mouse model demonstrated a significant reduction in ear edema. The extracts were further tested on purified enzymes for COX-1 and COX-2 inhibition to elucidate their mechanism of action, and a strong inhibition was observed. Six anthraquinones and two naphthalene derivatives were isolated from the ethyl acetate extract. Among the isolated compounds, emodin was found to be a potent inhibitor with slight selectivity towards COX-2, and nepodin exhibited selectivity towards COX-1. Emodin, endocrocin, and nepodin also exhibited significant topical anti-inflammatory activity in mice. Interestingly, nepodin showed better radical scavenging activity than trolox and ascorbic acid against DPPH and ABTS radicals. The strong radical scavenging activity of chloroform and ethyl acetate extracts could be explained by the presence of nepodin as well as by the high phenolic content of the ethyl acetate extract. Thus, the anti-inflammatory effect of R. NEPALENSIS roots was assumed to be mediated through COX inhibition by anthraquinones and naphthalene derivatives and through the radical scavenging activities of naphthalene derivatives. © Georg Thieme Verlag KG Stuttgart · New York.

Effect of platelets on apparent leucocyte ascorbic acid content.

PubMed

Evans, R M; Currie, L; Campbell, A

1980-09-01

The leucocyte ascorbic acid content is widely used as a measure of tissue ascorbic acid status. Standard methods of analysis, however, isolate both leucocytes and platelets (buffy layer), with consequent overestimation, since platelet ascorbic acid is attributed to the leucocytes. Fourteen healthy individuals on ascorbic acid supplements and 11 patients on mega dose ascorbic acid therapy were studied. A significant correlation was demonstrated between the 'leucocyte' ascorbic acid content and the platelet: leucocyte ratio (r = 0.70, P < 0.001). It is suggested that changes in the relative distribution of platelets and leucocytes in the blood will result in an apparent change in the 'leucocyte' ascorbic acid content regardless of any actual change in the ascorbic acid content of the cells.

Ascorbic acid insufficiency induces the severe defect on bone formation via the down-regulation of osteocalcin production

PubMed Central

Kim, Won; Bae, Seyeon; Kim, Hyemin; Kim, Yejin; Choi, Jiwon; Lim, Sun Young; Lee, Hei Jin; Lee, Jihyuk; Choi, Jiyea; Jang, Mirim; Lee, Kyoung Eun; Chung, Sun G.; Hwang, Young-il

2013-01-01

The L-gulono-γ-lactone oxidase gene (Gulo) encodes an essential enzyme in the synthesis of ascorbic acid from glucose. On the basis of previous findings of bone abnormalities in Gulo-/- mice under conditions of ascorbic acid insufficiency, we investigated the effect of ascorbic acid insufficiency on factors related to bone metabolism in Gulo-/- mice. Four groups of mice were raised for 4 weeks under differing conditions of ascorbic acid insufficiency, namely, wild type; ascorbic acid-sufficient Gulo-/- mice, 3-week ascorbic acid-insufficient Gulo-/- mice, and 4-week ascorbic acid-insufficient Gulo-/- mice. Four weeks of ascorbic acid insufficiency resulted in significant weight loss in Gulo-/- mice. Interestingly, average plasma osteocalcin levels were significantly decreased in Gulo-/- mice after 3 weeks of ascorbic acid insufficiency. In addition, the tibia weight in ascorbic acid-sufficient Gulo-/- mice was significantly higher than that in the other three groups. Moreover, significant decreases in trabecular bone volume near to the growth plate, as well as in trabecular bone attachment to the growth plate, were evident in 3- or 4-week ascorbic acid-insufficient Gulo-/-. In summary, ascorbic acid insufficiency in Gulo-/- mice results in severe defects in normal bone formation, which are closely related to a decrease in plasma osteocalcin levels. PMID:24386598

Vitamin C in human health and disease is still a mystery ? An overview

PubMed Central

Naidu, K Akhilender

2003-01-01

Ascorbic acid is one of the important water soluble vitamins. It is essential for collagen, carnitine and neurotransmitters biosynthesis. Most plants and animals synthesize ascorbic acid for their own requirement. However, apes and humans can not synthesize ascorbic acid due to lack of an enzyme gulonolactone oxidase. Hence, ascorbic acid has to be supplemented mainly through fruits, vegetables and tablets. The current US recommended daily allowance (RDA) for ascorbic acid ranges between 100–120 mg/per day for adults. Many health benefits have been attributed to ascorbic acid such as antioxidant, anti-atherogenic, anti-carcinogenic, immunomodulator and prevents cold etc. However, lately the health benefits of ascorbic acid has been the subject of debate and controversies viz., Danger of mega doses of ascorbic acid? Does ascorbic acid act as a antioxidant or pro-oxidant ? Does ascorbic acid cause cancer or may interfere with cancer therapy? However, the Panel on dietary antioxidants and related compounds stated that the in vivo data do not clearly show a relationship between excess ascorbic acid intake and kidney stone formation, pro-oxidant effects, excess iron absorption. A number of clinical and epidemiological studies on anti-carcinogenic effects of ascorbic acid in humans did not show any conclusive beneficial effects on various types of cancer except gastric cancer. Recently, a few derivatives of ascorbic acid were tested on cancer cells, among them ascorbic acid esters showed promising anticancer activity compared to ascorbic acid. Ascorbyl stearate was found to inhibit proliferation of human cancer cells by interfering with cell cycle progression, induced apoptosis by modulation of signal transduction pathways. However, more mechanistic and human in vivo studies are needed to understand and elucidate the molecular mechanism underlying the anti-carcinogenic property of ascorbic acid. Thus, though ascorbic acid was discovered in 17th century, the exact role of this vitamin/nutraceutical in human biology and health is still a mystery in view of many beneficial claims and controversies. PMID:14498993

Ascorbic acid deficiency stimulates hepatic expression of inflammatory chemokine, cytokine-induced neutrophil chemoattractant-1, in scurvy-prone ODS rats.

PubMed

Horio, Fumihiko; Kiyama, Keiichiro; Kobayashi, Misato; Kawai, Kaori; Tsuda, Takanori

2006-02-01

ODS rat has a hereditary defect in ascorbic acid biosynthesis and is a useful animal model for elucidating the physiological role of ascorbic acid. We previously demonstrated by using ODS rats that ascorbic acid deficiency changes the hepatic gene expression of acute phase proteins, as seen in acute inflammation. In this study, we investigated the effects of ascorbic acid deficiency on the production of inflammatory chemokine, cytokine-induced neutrophil chemoattractant-1 (CINC-1), in ODS rats. Male ODS rats (6 wk of age) were fed a basal diet containing ascorbic acid (300 mg/kg diet) or a diet without ascorbic acid for 14 d. Obvious symptoms of scurvy were not observed in the ascorbic acid-deficient rats. Ascorbic acid deficiency significantly elevated the serum concentration of CINC-1 on d 14. The liver and spleen CINC-1 concentrations in the ascorbic acid-deficient rats were significantly elevated to 600% and 180% of the respective values in the control rats. However, the lung concentration of CINC-1 was not affected by ascorbic acid deficiency. Ascorbic acid deficiency significantly elevated the hepatic mRNA level of CINC-1 (to 480% of the value in the control rats), but not the lung mRNA level. These results demonstrate that ascorbic acid deficiency elevates the serum, liver and spleen concentrations of CINC-1 as seen in acute inflammation, and suggest that ascorbic acid deficiency stimulate the hepatic CINC-1 gene expression.

Higher transcription levels in ascorbic acid biosynthetic and recycling genes were associated with higher ascorbic acid accumulation in blueberry.

PubMed

Liu, Fenghong; Wang, Lei; Gu, Liang; Zhao, Wei; Su, Hongyan; Cheng, Xianhao

2015-12-01

In our preliminary study, the ripe fruits of two highbush blueberry (Vaccinium corymbosum L.) cultivars, cv 'Berkeley' and cv 'Bluecrop', were found to contain different levels of ascorbic acid. However, factors responsible for these differences are still unknown. In the present study, ascorbic acid content in fruits was compared with expression profiles of ascorbic acid biosynthetic and recycling genes between 'Bluecrop' and 'Berkeley' cultivars. The results indicated that the l-galactose pathway was the predominant route of ascorbic acid biosynthesis in blueberry fruits. Moreover, higher expression levels of the ascorbic acid biosynthetic genes GME, GGP, and GLDH, as well as the recycling genes MDHAR and DHAR, were associated with higher ascorbic acid content in 'Bluecrop' compared with 'Berkeley', which indicated that a higher efficiency ascorbic acid biosynthesis and regeneration was likely to be responsible for the higher ascorbic acid accumulation in 'Bluecrop'. Copyright © 2015 Elsevier Ltd. All rights reserved.

Radical scavenging activity of selected medicinal plants from Limpopo province of South Africa.

PubMed

Chauke, A M; Shai, L J; Mphahlele, P M; Mogale, M A

2012-01-01

Plants collected from Limpopo province of South Africa were investigated for their antioxidative potential using the DPPH radical scavenging assay. Acetone extracts of Flueggea virosa had the highest antioxidant activity with an IC₅₀ value of 30 µg/ml, closely matching the ascorbic acid with an IC₅₀ value of 25 µg/ml. The lowest antioxidant readings were observed with extracts of Rhynchosia venulosa (root extract) and Ficus ingens (leaf extract). Acetone extract of Bridelia virosa leaves had the highest phenolic content (156 mg GAE/g extract), while the lowest content was recorded for R. venulosa root extract and leaf extract of F. ingens (8.3 and 17.7 mg GAE/g extract, respectively). There was a linear correlation between antioxidant activity and total phenolic content. Extracts with high phenolic content had low IC₅₀ values, while extracts with low phenolic concentrations had high IC₅₀ values.

Pulmonary bioavailability of ascorbic acid in an ascorbate-synthesising species, the horse.

PubMed

Deaton, Christopher M; Marlin, David J; Smith, Nicola C; Roberts, Colin A; Harris, Pat A; Kelly, Frank J; Schroter, Robert C

2003-04-01

Vitamin C (ascorbic acid) is a non-enzymatic antioxidant important in protecting the lung against oxidative damage and is decreased in lung lining fluid of horses with airway inflammation. To examine possible therapeutic regimens in a species with ascorbate-synthesising capacity, we studied the effects of oral supplementation of two forms of ascorbic acid, (each equivalent to 20 mg ascorbic acid per kg body weight) on the pulmonary and systemic antioxidant status of six healthy ponies in a 3 x 3 Latin square design. Two weeks supplementation with ascorbyl palmitate significantly increased mean plasma ascorbic acid concentrations compared to control (29 +/- 5 and 18 +/- 7 micromol/l, respectively; p < 0.05). Calcium ascorbyl-2-monophosphate, a more stable form of ascorbic acid, also increased mean plasma ascorbic acid concentrations, but not significantly (23 +/- 1 micromol/l; p = 0.07). The concentration of ascorbic acid in bronchoalveolar lavage fluid increased in five out of six ponies following supplementation with either ascorbyl palmitate or calcium ascorbyl-2-monophosphate compared with control (30 +/- 10, 25 +/- 4 and 18 +/- 8 micromol/l, respectively; p < 0.01). Neither supplement altered the concentration of glutathione, uric acid or alpha-tocopherol in plasma or bronchoalveolar lavage fluid. In conclusion, the concentration of lung lining fluid ascorbic acid is increased following ascorbic acid supplementation (20 mg/kg body weight) in an ascorbate-synthesising species.

Comparative assessment on in vitro antioxidant activities of ethanol extracts of Averrhoa bilimbi, Gymnema sylvestre and Capsicum frutescens

PubMed Central

Rahman, Md. Mominur; Habib, Md. Razibul; Hasan, Md. Anayet; Al Amin, Mohammad; Saha, Ayan; Mannan, Adnan

2014-01-01

Background: Averrhoa bilimbi, Gymnema sylvestre and Capsicum frutescens are medicinal plants commonly used as traditional medicine for the treatment of various diseases. The present study was designed to investigate the antioxidant activities of Ethanolic extract of A. bilimbi, G. sylvestre and C. frutescens. Materials and Methods: The antioxidant activity of the extracts were evaluated using total phenolic and flavonoid contents, ferric reducing power and the free radical scavenging activity against 1,1-diphenyl-2-picrylhydrazyl (DPPH). Results: Total phenolic and flavonoid contents were higher in G. sylvestre (53.63636 ± 0.454545 mg/g gallic acid equivalent) and C. frutescens (26.66667 ± 2.081666 mg/g quercetin equivalent) respectively. Reducing power of the crude ethanol extracts increased with the concentrations of the extracts and all the extracts showed moderate free radical scavenging activity against DPPH. The plant extract displayed moderate phenolic and flavonoid contents compared to gallic acid and quercetin equivalent respectively, whereas also exhibited significant scavenging of DPPH radical and reducing power compared with ascorbic acid as standard. Conclusion: Our study suggests that G. sylvestre has significant antioxidant activity. The antioxidant compound of this plant might be a therapeutic candidate against oxidative stress related diseases. Different sub-fraction of A. bilimbi and C. frutescens should be studied further to assess the effect. Further study is necessary for isolation and characterization of the active antioxidant agents for better treatment. PMID:24497740

Phytochemical analysis, antioxidant activity, fatty acids composition, and functional group analysis of Heliotropium bacciferum.

PubMed

Ahmad, Sohail; Ahmad, Shabir; Bibi, Ahtaram; Ishaq, Muhammad Saqib; Afridi, Muhammad Siddique; Kanwal, Farina; Zakir, Muhammad; Fatima, Farid

2014-01-01

Heliotropium bacciferum is paramount in medicinal perspective and belongs to Boraginaceae family. The crude and numerous fractions of leaves, stem, and roots of the plant were investigated for phytochemical analysis and DPPH radical scavenging activity. Phytochemical analysis of crude and fractions of the plant revealed the presence of alkaloids, saponins, tannins, steroids, terpenoids, flavonoids, glycosides, and phenols. The antioxidant (free radical scavenging) activity of various extracts of the Heliotropium bacciferum was resolute against 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical with the avail of UV spectrophotometer at 517 nm. The stock solution (1000 mg/mL) and then several dilutions (50, 100, 150, 200, and 250 mg/mL) of the crude and fractions were prepared. Ascorbic acid was used as a standard. The plant leaves (52.59 ± 0.84 to 90.74 ± 1.00), stem (50.19 ± 0.92 to 89.42 ± 1.10), and roots extracts (49.19 ± 0.52 to 90.01 ± 1.02) divulged magnificent antioxidant activities. For the ascertainment of the fatty acid constituents a gas chromatograph hyphenated to mass spectrometer was used. The essential fatty acids for growth maintenance such as linoleic acid (65.70%), eicosadienoic acid (15.12%), oleic acid (8.72%), and palmitic acid (8.14%) were found in high percentage. The infrared spectra of all extracts of the plant were recorded by IR Prestige-21 FTIR model.

Phytochemical Analysis, Antioxidant Activity, Fatty Acids Composition, and Functional Group Analysis of Heliotropium bacciferum

PubMed Central

Ahmad, Sohail; Ahmad, Shabir; Bibi, Ahtaram; Ishaq, Muhammad Saqib; Afridi, Muhammad Siddique; Kanwal, Farina; Zakir, Muhammad; Fatima, Farid

2014-01-01

Heliotropium bacciferum is paramount in medicinal perspective and belongs to Boraginaceae family. The crude and numerous fractions of leaves, stem, and roots of the plant were investigated for phytochemical analysis and DPPH radical scavenging activity. Phytochemical analysis of crude and fractions of the plant revealed the presence of alkaloids, saponins, tannins, steroids, terpenoids, flavonoids, glycosides, and phenols. The antioxidant (free radical scavenging) activity of various extracts of the Heliotropium bacciferum was resolute against 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical with the avail of UV spectrophotometer at 517 nm. The stock solution (1000 mg/mL) and then several dilutions (50, 100, 150, 200, and 250 mg/mL) of the crude and fractions were prepared. Ascorbic acid was used as a standard. The plant leaves (52.59 ± 0.84 to 90.74 ± 1.00), stem (50.19 ± 0.92 to 89.42 ± 1.10), and roots extracts (49.19 ± 0.52 to 90.01 ± 1.02) divulged magnificent antioxidant activities. For the ascertainment of the fatty acid constituents a gas chromatograph hyphenated to mass spectrometer was used. The essential fatty acids for growth maintenance such as linoleic acid (65.70%), eicosadienoic acid (15.12%), oleic acid (8.72%), and palmitic acid (8.14%) were found in high percentage. The infrared spectra of all extracts of the plant were recorded by IR Prestige-21 FTIR model. PMID:25489605

Effect of Freeze-Drying on the Antioxidant Compounds and Antioxidant Activity of Selected Tropical Fruits

PubMed Central

Shofian, Norshahida Mohamad; Hamid, Azizah Abdul; Osman, Azizah; Saari, Nazamid; Anwar, Farooq; Dek, Mohd Sabri Pak; Hairuddin, Muhammad Redzuan

2011-01-01

The effects of freeze-drying on antioxidant compounds and antioxidant activity of five tropical fruits, namely starfruit (Averrhoa carambola L.), mango (Mangifera indica L.), papaya (Carica papaya L.), muskmelon (Cucumis melo L.), and watermelon Citruluss lanatus (Thunb.) were investigated. Significant (p < 0.05) differences, for the amounts of total phenolic compounds (TPC), were found between the fresh and freeze-dried fruit samples, except muskmelon. There was no significant (p > 0.05) change, however, observed in the ascorbic acid content of the fresh and freeze-dried fruits. Similarly, freeze-drying did not exert any considerable effect on β-carotene concentration of fruits, except for mango and watermelon, where significantly (p < 0.05) higher levels were detected in the fresh samples. The results of DPPH (2,2-diphenyl-1-picrylhydrazyl) radical scavenging and reducing power assays revealed that fresh samples of starfruit and mango had relatively higher antioxidant activity. In case of linoleic acid peroxidation inhibition measurement, a significant (p < 0.05) but random variation was recorded between the fresh and freeze-dried fruits. Overall, in comparison to β-carotene and ascorbic acid, a good correlation was established between the result of TPC and antioxidant assays, indicating that phenolics might have been the dominant compounds contributing towards the antioxidant activity of the fruits tested. PMID:21845104

Effect of freeze-drying on the antioxidant compounds and antioxidant activity of selected tropical fruits.

PubMed

Shofian, Norshahida Mohamad; Hamid, Azizah Abdul; Osman, Azizah; Saari, Nazamid; Anwar, Farooq; Dek, Mohd Sabri Pak; Hairuddin, Muhammad Redzuan

2011-01-01

The effects of freeze-drying on antioxidant compounds and antioxidant activity of five tropical fruits, namely starfruit (Averrhoa carambola L.), mango (Mangifera indica L.), papaya (Carica papaya L.), muskmelon (Cucumis melo L.), and watermelon Citruluss lanatus (Thunb.) were investigated. Significant (p < 0.05) differences, for the amounts of total phenolic compounds (TPC), were found between the fresh and freeze-dried fruit samples, except muskmelon. There was no significant (p > 0.05) change, however, observed in the ascorbic acid content of the fresh and freeze-dried fruits. Similarly, freeze-drying did not exert any considerable effect on β-carotene concentration of fruits, except for mango and watermelon, where significantly (p < 0.05) higher levels were detected in the fresh samples. The results of DPPH (2,2-diphenyl-1-picrylhydrazyl) radical scavenging and reducing power assays revealed that fresh samples of starfruit and mango had relatively higher antioxidant activity. In case of linoleic acid peroxidation inhibition measurement, a significant (p < 0.05) but random variation was recorded between the fresh and freeze-dried fruits. Overall, in comparison to β-carotene and ascorbic acid, a good correlation was established between the result of TPC and antioxidant assays, indicating that phenolics might have been the dominant compounds contributing towards the antioxidant activity of the fruits tested.

Antioxidative characteristics and inhibition of alpha-melanocyte-stimulating hormone-stimulated melanogenesis of vanillin and vanillic acid from Origanum vulgare.

PubMed

Chou, Tzung-Han; Ding, Hsiou-Yu; Hung, Wei Jing; Liang, Chia-Hua

2010-08-01

The antioxidant activities of vanillin and vanillic acid isolated from Origanum vulgare are investigated. These compounds may serve as agents for antimelanogenesis. Vanillic acid is a stronger antioxidant than vanillin, in terms of free radical scavenging activity, reducing power and inhibition of lipid peroxidation. The inhibition of cellular reactive oxygen species (ROS) in H(2)O(2)-treated BNLCL2 cells by vanillic acid exceeds that of ascorbic acid (AA) or trolox. In B16F0 cells stimulated with alpha-melanocyte-stimulating hormone (alpha-MSH), vanillic acid reduced cellular tyrosinase activity, DOPA oxidase and melanin contents, as well as down-regulated expressions of melanocortin-1 receptor (MC1R), microphthalmia-associated transcription factor (MITF), tyrosinase, tyrosinase-related proteins 2 (TRP-2) and TRP-1. Vanillin did not express inhibition of tyrosinase activity. These results supported that vanillic acid is a significantly stronger antioxidant than vanillin and exhibited stronger antimelanogenesis performance because of the structural presence of the carboxyl group.

Effect of docosahexaenoic acid and ascorbate on peroxidation of retinal membranes of ODS rats.

PubMed

Wang, Jin-Ye; Sekine, Seiji; Saito, Morio

2003-04-01

Mutant male osteogenic disorder Shionogi (ODS) rats, unable to synthesize ascorbic acid, were fed diets containing a high content of docosahexaenoic acid (DHA) and different amounts of ascorbic acid, to study the effect of DHA on peroxidative susceptibility of the retina and possible antioxidant action of ascorbic acid. ODS rats were fed from 7 weeks of age with diets containing high DHA (6.4% of total energy). A control group received a diet high in linoleic acid. The diets also contained varying amounts of ascorbic acid. Fatty acid compositions and phospholipid hydroperoxides in rod outer segment (ROS) membranes, and retinal ascorbic acid were analyzed. DHA in ROS membranes was significantly increased in rats fed high DHA, compared with the linoleic acid diet. Levels of phospholipid hydroperoxides in the DHA-fed rats were significantly higher than the linoleic acid-fed rats. Ascorbic acid supplementation did not suppress the phospholipid hydroperoxide levels after a high DHA diet, even when the supplement increased the content of retinal ascorbic acid. In conclusion, high DHA feeding induced a marked increase of phospholipid hydroperoxides in ROS membranes of ODS rats. Supplementation of ascorbic acid did not reverse this increase.

An acute study on the relative gastro-intestinal absorption of a novel form of calcium ascorbate.

PubMed

Bush, M J; Verlangieri, A J

1987-07-01

Several functions of L-ascorbic acid (vitamin C) have been suggested in addition to its role in the prevention of scurvy. Consequently, a controversy has arisen over the daily intake of the vitamin which will afford maximum benefits. Rapid cellular uptake and delayed renal excretion of ascorbic acid would be conducive to providing optimum cellular concentration for biochemical activity. ESTER-C (patent pending), a complex consisting of L-ascorbic acid and Ca++, has been recently developed by Inter-Cal Corporation (421 Miller Road, Prescott, AZ 86301). It has been proposed that the structure of ESTER-C may render it more readily absorbed and less rapidly excreted than the acid or salt form of the vitamin. To test this hypothesis, ESTER-C and L-ascorbic acid were administered to two groups of rats. Blood was sampled at 20, 40, 80, 160 and 240 minutes and plasma analyzed for ascorbic acid. As urine appeared in collection cups, it was tested qualitatively for the presence of ascorbic acid. The plasma concentration of ascorbic acid was higher in ESTER-C treated rats at 20, 40 and 80 minutes than in rats given L-ascorbic acid. Ascorbic acid was detected in the urine of animals administered ESTER-C later than in those treated with L-ascorbic acid. These results support the hypothesis that ESTER-C is absorbed more readily and excreted less rapidly than L-ascorbic acid.

Mechanism of action of vitamin C in sepsis: Ascorbate modulates redox signaling in endothelium

PubMed Central

Wilson, John X.

2009-01-01

Circulating levels of vitamin C (ascorbate) are low in patients with sepsis. Parenteral administration of ascorbate raises plasma and tissue concentrations of the vitamin and may decrease morbidity. In animal models of sepsis, intravenous ascorbate injection increases survival and protects several microvascular functions, namely, capillary blood flow, microvascular permeability barrier, and arteriolar responsiveness to vasoconstrictors and vasodilators. The effects of parenteral ascorbate on microvascular function are both rapid and persistent. Ascorbate quickly accumulates in microvascular endothelial cells, scavenges reactive oxygen species, and acts through tetrahydrobiopterin to stimulate nitric oxide production by endothelial nitric oxide synthase. A major reason for the long duration of the improvement in microvascular function is that cells retain high levels of ascorbate, which alter redox-sensitive signaling pathways to diminish septic induction of NADPH oxidase and inducible nitric oxide synthase. These observations are consistent with the hypothesis that microvascular function in sepsis may be improved by parenteral administration of ascorbate as an adjuvant therapy. PMID:19319840

Final report of the safety assessment of L-Ascorbic Acid, Calcium Ascorbate, Magnesium Ascorbate, Magnesium Ascorbyl Phosphate, Sodium Ascorbate, and Sodium Ascorbyl Phosphate as used in cosmetics.

PubMed

Elmore, Amy R

2005-01-01

L-Ascorbic Acid, Calcium Ascorbate, Magnesium Ascorbate, Magnesium Ascorbyl Phosphate, Sodium Ascorbate, and Sodium Ascorbyl Phosphate function in cosmetic formulations primarily as antioxidants. Ascorbic Acid is commonly called Vitamin C. Ascorbic Acid is used as an antioxidant and pH adjuster in a large variety of cosmetic formulations, over 3/4 of which were hair dyes and colors at concentrations between 0.3% and 0.6%. For other uses, the reported concentrations were either very low (<0.01%) or in the 5% to 10% range. Calcium Ascorbate and Magnesium Ascorbate are described as antioxidants and skin conditioning agents--miscellaneous for use in cosmetics, but are not currently used. Sodium Ascorbyl Phosphate functions as an antioxidant in cosmetic products and is used at concentrations ranging from 0.01% to 3%. Magnesium Ascorbyl Phosphate functions as an antioxidant in cosmetics and was reported being used at concentrations from 0.001% to 3%. Sodium Ascorbate also functions as an antioxidant in cosmetics at concentrations from 0.0003% to 0.3%. Related ingredients (Ascorbyl Palmitate, Ascorbyl Dipalmitate, Ascorbyl Stearate, Erythorbic Acid, and Sodium Erythorbate) have been previously reviewed by the Cosmetic Ingredient Review (CIR) Expert Panel and found "to be safe for use as cosmetic ingredients in the present practices of good use." Ascorbic Acid is a generally recognized as safe (GRAS) substance for use as a chemical preservative in foods and as a nutrient and/or dietary supplement. Calcium Ascorbate and Sodium Ascorbate are listed as GRAS substances for use as chemical preservatives. L-Ascorbic Acid is readily and reversibly oxidized to L-dehydroascorbic acid and both forms exist in equilibrium in the body. Permeation rates of Ascorbic Acid through whole and stripped mouse skin were 3.43 +/- 0.74 microg/cm(2)/h and 33.2 +/- 5.2 microg/cm(2)/h. Acute oral and parenteral studies in mice, rats, rabbits, guinea pigs, dogs, and cats demonstrated little toxicity. Ascorbic Acid and Sodium Ascorbate acted as a nitrosation inhibitor in several food and cosmetic product studies. No compound-related clinical signs or gross or microscopic pathological effects were observed in either mice, rats, or guinea pigs in short-term studies. Male guinea pigs fed a control basal diet and given up to 250 mg Ascorbic Acid orally for 20 weeks had similar hemoglobin, blood glucose, serum iron, liver iron, and liver glycogen levels compared to control values. Male and female F344/N rats and B6C3F(1) mice were fed diets containing up to 100,000 ppm Ascorbic Acid for 13 weeks with little toxicity. Chronic Ascorbic Acid feeding studies showed toxic effects at dosages above 25 mg/kg body weight (bw) in rats and guinea pigs. Groups of male and female rats given daily doses up to 2000 mg/kg bw Ascorbic Acid for 2 years had no macro- or microscopically detectable toxic lesions. Mice given Ascorbic Acid subcutaneous and intravenous daily doses (500 to 1000 mg/kg bw) for 7 days had no changes in appetite, weight gain, and general behavior; and histological examination of various organs showed no changes. Ascorbic Acid was a photoprotectant when applied to mice and pig skin before exposure to ultraviolet (UV) radiation. The inhibition of UV-induced suppression of contact hypersensitivity was also noted. Magnesium Ascorbyl Phosphate administration immediately after exposure in hairless mice significantly delayed skin tumor formation and hyperplasia induced by chronic exposure to UV radiation. Pregnant mice and rats were given daily oral doses of Ascorbic Acid up to 1000 mg/kg bw with no indications of adult-toxic, teratogenic, or fetotoxic effects. Ascorbic Acid and Sodium Ascorbate were not genotoxic in several bacterial and mammalian test systems, consistent with the antioxidant properties of these chemicals. In the presence of certain enzyme systems or metal ions, evidence of genotoxicity was seen. The National Toxicology Program (NTP) conducted a 2-year oral carcinogenesis bioassay of Ascorbic Acid (25,000 and 50,000 ppm) in F344/N rats and B6C3F(1) mice. Ascorbic Acid was not carcinogenic in either sex of both rats and mice. Inhibition of carcinogenesis and tumor growth related to Ascorbic Acid's antioxidant properties has been reported. Sodium Ascorbate has been shown to promote the development of urinary carcinomas in two-stage carcinogenesis studies. Dermal application of Ascorbic Acid to patients with radiation dermatitis and burn victims had no adverse effects. Ascorbic Acid was a photoprotectant in clinical human UV studies at doses well above the minimal erythema dose (MED). An opaque cream containing 5% Ascorbic Acid did not induce dermal sensitization in 103 human subjects. A product containing 10% Ascorbic Acid was nonirritant in a 4-day minicumulative patch assay on human skin and a facial treatment containing 10% Ascorbic Acid was not a contact sensitizer in a maximization assay on 26 humans. Because of the structural and functional similarities of these ingredients, the Panel believes that the data on one ingredient can be extrapolated to all of them. The Expert Panel attributed the finding that Ascorbic Acid was genotoxic in these few assay systems due to the presence of other chemicals, e.g., metals, or certain enzyme systems, which effectively convert Ascorbic Acid's antioxidant action to that of a pro-oxidant. When Ascorbic Acid acts as an antioxidant, the Panel concluded that Ascorbic Acid is not genotoxic. Supporting this view were the carcinogenicity studies conducted by the NTP, which demonstrated no evidence of carcinogenicity. Ascorbic Acid was found to effectively inhibit nitrosamine yield in several test systems. The Panel did review studies in which Sodium Ascorbate acted as a tumor promoter in animals. These results were considered to be related to the concentration of sodium ions and the pH of urine in the test animals. Similar effects were seen with sodium bicarbonate. Because of the concern that certain metal ions may combine with these ingredients to produce pro-oxidant activity, the Panel cautioned formulators to be certain that these ingredients are acting as antioxidants in cosmetic formulations. The Panel believed that the clinical experience in which Ascorbic Acid was used on damaged skin with no adverse effects and the repeat-insult patch test (RIPT) using 5% Ascorbic Acid with negative results supports the finding that this group of ingredients does not present a risk of skin sensitization. These data coupled with an absence of reports in the clinical literature of Ascorbic Acid sensitization strongly support the safety of these ingredients.

Beneficial effects of Bacopa monnieri extract on opioid induced toxicity.

PubMed

Shahid, Muhammad; Subhan, Fazal; Ullah, Ihsan; Ali, Gowhar; Alam, Javaid; Shah, Rehmat

2016-02-01

The present study examined the hepatotoxicity and nephrotoxicity of morphine and illicit street heroin and their amelioration by a standardized methanolic extract of Bacopa monnieri (L.) (mBME) in rats. Morphine or street heroin was administered at a dose of 20 mg/kg for 14 and 21 days. mBME (40 mg/kg) or ascorbic acid (50 mg/kg) was administered two hours before morphine or street heroin. High performance liquid chromatography (HPLC) was used for the standardization of bacoside-A major components in mBME. The antioxidant potential of mBME was evaluated by 2,2-diphenyl-1-picrylhydrazyl (DPPH) free radical scavenging assay. Administration of morphine and street heroin resulted in marked elevation of serum alanine aminotransferase (ALT), aspartate aminotransferase (AST) and creatinine. Histopathological changes induced by morphine and street heroin after 14 days were of reversible nature while treatment for 21 days was associated with irreversible changes. Pretreatment with mBME or ascorbic acid restored the elevation of serum ALT, AST and creatinine and protected liver and kidneys from the toxicological influence of morphine and street heroin. HPLC analysis showed that mBME contained bacoside-A major components i.e. bacoside-A3 (37.5 μg/mg), bacopaside-II (4.62 μg/mg) and bacopasaponin-C (1.91 μg/mg). The EC50 for the DPPH free radical scavenging assay revealed that mBME possessed strong antioxidant potential. These results concluded that as compared to morphine, street heroin was associated with severe biochemical and histopathological changes in the liver and kidneys. Bacopa monnieri having strong antioxidant potential may provide a beneficial herbal remedy for the efficient management of opioid related hepatotoxicity and nephrotoxicity.

High-dose ascorbic acid induces carcinostatic effects through hydrogen peroxide and superoxide anion radical generation-induced cell death and growth arrest in human tongue carcinoma cells.

PubMed

Ohwada, Ryouhei; Ozeki, Yu; Saitoh, Yasukazu

2017-01-01

High-dose ascorbic acid (AsA) treatment, known as pharmacological AsA, has been shown to exert carcinostatic effects in many types of cancer cells and in vivo tumour models. Although pharmacological AsA has potential as a complementary and alternative medicine for anticancer treatment, its effects on human tongue carcinoma have not yet been elucidated. In this study, we investigated the effect of AsA treatment on human tongue carcinoma HSC-4 cells compared with non-tumourigenic tongue epithelial dysplastic oral keratinocyte (DOK) cells. Our results show that treatment with 1 and 3 mM of AsA for 60 min preferentially inhibits the growth of human tongue carcinoma HSC-4 over DOK cells. Furthermore, AsA-induced effects were accompanied by increased intracellular oxidative stress and were repressed by treatment with a hydrogen peroxide (H 2 O 2 ) scavenger catalase and a superoxide anion radical (O 2 - ) scavenger, tempol. Time-lapse observation and thymidine analog EdU incorporation revealed that AsA treatment induces not only cell death but also suppression of DNA synthesis and cell growth. Moreover, the growth arrest was accompanied by abnormal cellular morphologies whereby cells extended dendrite-like pseudopodia. Taken together, our results demonstrate that AsA treatment can induce carcinostatic effects through induction of cell death, growth arrest, and morphological changes mediated by H 2 O 2 and O 2 - generation. These findings suggest that high-dose AsA treatment represents an effective treatment for tongue cancer as well as for other types of cancer cells.

Effects of hot air and freeze drying methods on antioxidant activity, colour and some nutritional characteristics of strawberry tree (Arbutus unedo L) fruit.

PubMed

Orak, H H; Aktas, T; Yagar, H; İsbilir, S Selen; Ekinci, N; Sahin, F Hasturk

2012-08-01

Antioxidant activity, colour and some nutritional properties of hot air and freeze-dried strawberry tree (Arbutus unedo L.) fruits were investigated. Additionally, the effects of two pre-treatments, namely ethyl oleate and water blanching, were compared in terms of drying characteristics. For determination of antioxidant activities in ethanol extracts, two different analytical methods were used: 1,1-diphenyl-2-picrylhydrazyl scavenging activity and β-carotene bleaching activity. As a result, the ethyl oleate pre-treatment shortened the drying time by hot air method and gave a higher 1,1-diphenyl-2-picrylhydrazyl scavenging activity (82.16 ± 0.34%), total phenolic content (7.62 ± 1.09 µg GAE/g extract), ascorbic acid content (236.93 ± 20.14 mg/100 g), besides hydromethylfurfural was not observed. Freeze-dried fruits exhibited higher ascorbic acid content (368.63 ± 17.16 mg/100 g) than those fresh fruits (231.33 ± 19.51 mg/100 g) and nearly 1,1-diphenyl-2-picrylhydrazyl activity (93.52 ± 0.41 %) to fresh fruits (94.03 ± 1.18%). Colour characteristics, sugar content and mineral contents of fruits were significantly affected by pre-treatments and drying methods (p < 0.05). It is concluded that the drying of strawberry tree fruits should bring a valuable and attractive foodstuff to food industry due to the rich nutritional components, antioxidant activity and colour. Another conclusion from this study is that the freeze-drying is the best drying method to keep the nutritional value, antioxidant activity and sensory properties of fruits.

Exogenous NO depletes Cd-induced toxicity by eliminating oxidative damage, re-establishing ATPase activity, and maintaining stress-related hormone equilibrium in white clover plants.

PubMed

Liu, S L; Yang, R J; Pan, Y Z; Wang, M H; Zhao, Y; Wu, M X; Hu, J; Zhang, L L; Ma, M D

2015-11-01

Various nitric oxide (NO) regulators [including the NO donor sodium nitroprusside (SNP), the NO scavenger 2-(4-carboxyphenyl)-4,4,5,5-tetramethylimidazoline-1-oxyl-3-oxide (cPTIO), the NO-synthase inhibitor N (G)-nitro-L-Arg-methyl ester (L-NAME), and the SNP analogues sodium nitrite/nitrate and sodium ferrocyanide] were investigated to elucidate the role of NO in white clover (Trifolium repens L.) plants after long-term (5 days) exposure to cadmium (Cd). A dose of 100 μM Cd stress significantly restrained plant growth and decreased the concentrations of chlorophyll and NO in vivo, whereas it disrupted the balance of stress-related hormones and enhanced the accumulation of Cd, thereby inducing reactive oxygen species (ROS) burst. However, the inhibition of plant growth was relieved by 50 μM SNP through its stimulation of ROS-scavenging compounds (ascorbic acid, ascorbate peroxidase, catalase, glutathione reductase, non-protein thiol, superoxide dismutase, and total glutathione), regulation of H(+)-ATPase activity of proton pumps, and increasing jasmonic acid and proline but decreasing ethylene in plant tissues. Even so, the alleviating effect of SNP on plant growth was counteracted by cPTIO and L-NAME and was not observed with SNP analogues, suggesting that the protective roles of SNP are related to the induction of NO. These results suggest that NO may improve the Cd tolerance of white clover plants by eliminating oxidative damage, re-establishing ATPase activity, and maintaining hormone equilibrium. Improving our understanding of the role of NO in white clover plants is key to expanding the plantations to various regions and the recovery of pasture species in the future.

Ascorbic acid as a free radical scavenger in porcine and bovine aqueous humour.

PubMed

Erb, Carl; Nau-Staudt, Kerstin; Flammer, Josef; Nau, Werner

2004-01-01

To study the antioxidant activity, UV absorption, concentration and stability of ascorbic acid (AA) in porcine and bovine aqueous humour (AH). Porcine and bovine AH was taken within 5 min after death and frozen at -70 degrees C. The characteristic UV absorption band of AA and the concentration of AA in AH was determined by UV spectrophotometry. The antioxidant activity of AA to serve as a free radical scavenger in AH has been determined by using a novel fluorescent probe for antioxidants, the azoalkane 2,3-diazabicyclo[2.2.2]oct-2-ene (DBO). The fluorescence lifetime and intensity of this probe reflect the concentration of dissolved antioxidants. The time-resolved fluorescence of DBO (laser excitation at 351 nm) in AH and in a neutral phosphate-buffered saline (PBS) solution containing only the natural amount of AA as an additive were measured. The characteristic UV absorption band of AA has its maximum at 266 nm in AH. The concentration of AA in porcine and bovine AH was found to be 0.547 +/- 0.044 and 1.09 +/- 0.16 mM, respectively, by spectrophotometry. The fluorescence lifetime of the probe DBO was reduced from 320 +/- 5 ns in pure aerated PBS to 205 +/- 5 ns in porcine AH and 165 +/- 3 ns in bovine AH. A detailed kinetic analysis of the lifetime shortening suggests that AA contributes approximately 75 and 85% to the antioxidant activity of porcine and bovine AH, respectively. Our experiments suggest that AA is the major contributor to the antioxidant activity of porcine and bovine AH. The role of AA to serve as an antioxidant in AH is discussed. In addition, UV spectrophotometry is established as an alternative method to determine the concentration of AA in AH. Copyright 2004 S. Karger AG, Basel

Screening chemical composition and in vitro antioxidant and antimicrobial activities of the essential oils from Origanum syriacum L. growing in Turkey.

PubMed

Alma, Mehmet Hakki; Mavi, Ahmet; Yildirim, Ali; Digrak, Metin; Hirata, Toshifumi

2003-12-01

In the present study, essential oil from the leaves of Syrian oreganum [Origanum syriacum L. (Lauraceae)] grown in Turkish state forests of the Dortyol district, Turkey, was obtained by steam distillation. The chemical composition of oil was analysed by GC and GC-MS, and was found to contain 49.02% monoterpenes, 36.60% oxygenated monoterpenes and 12.59% sesquiterpenes. The major components are as follows: gamma-terpinene, carvacrol, p-cymene and beta-caryophyllene. Subsequently, the reducing power, antioxidant and 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical-scavenging activities of the essential oil were studied. The reducing power was compared with ascorbic acid, and the other activities were compared with 2,6-di-tert-butyl-4-methyl phenol (BHT, butylated hydroxytoluene). The results showed that the activities were concentration dependent. The antioxidant activities of the oil were slightly lower than those of ascorbic acid or BHT, so the oil can be considered an effective natural antioxidant. Antimicrobial activities of the essential oil from the leaves of Origanum syriacum was also determined on 16 microorganisms tested using the agar-disc diffusion method, and showed antimicrobial activity against 13 of these.

Study of lipid peroxidation and ascorbic acid protective role in large unilamellar vesicles from a new electrochemical performance.

PubMed

Barroso, M Fátima; Luna, M Alejandra; Moyano, Fernando; Delerue-Matos, Cristina; Correa, N Mariano; Molina, Patricia G

2018-04-01

In this contribution an electrochemical study is described for the first time of lipid peroxidation and the role of antioxidant on lipid protection using large unilamellar vesicles (LUVs). In order to simulate the cell membrane, LUVs composed of 1,2-dioleoyl-sn-glycero-3-phosphocholine (DOPC) were used. A vesicle-modified electrode was constructed by immobilizing DOPC LUVs onto carbon paste electrodes (CPEs). Lipid peroxidation was studied electrochemically by incubating the vesicle-modified electrodes with hydroxyl (HO) radicals generated via the Fenton reaction. Oxidative damage induced by HO was verified by using square wave voltammetry (SWV) and was indirectly measured by the increase of electrochemical peak current to [Fe(CN) 6 ] 4- which was used as the electrochemical label. Ascorbic acid (AA) was used as the antioxidant model in order to study its efficacy on free radical scavenging. The decrease of the electrochemical signal confirms the protective key role promoted by AA in the prevention of lipid peroxidation in vesicles. Through microscopy, it was possible to observe morphologic modification on vesicle structures after lipid peroxidation in the presence or absence of AA. Copyright © 2017 Elsevier B.V. All rights reserved.

Perturbations in carotenoid and porphyrin status result in differential photooxidative stress signaling and antioxidant responses.

PubMed

Park, Joon-Heum; Jung, Sunyo

2018-02-12

We examined differential photooxidative stress signaling and antioxidant responses in rice plants treated with norflurazon (NF) and oxyfluorfen (OF), which are inhibitors of carotenoid and porphyrin biosynthesis, respectively. Plants treated with OF markedly increased levels of cellular leakage and malondialdehyde, compared with NF-treated plants, showing that OF plants suffered greater oxidative damage with respect to membrane integrity. The enhanced production of H 2 O 2 in response to OF, but not NF, indicates the important role of H 2 O 2 in activation of photooxidative stress signaling in OF plants. In response to NF and OF, the increased levels of free salicylic acid as well as maintenance of the redox ratio of ascorbate and glutathione pools to a certain level are considered to be crucial factors in the protection against photooxidation. Plants treated with OF greatly up-regulated catalase (CAT) activity and Cat transcript levels, compared with NF-treated plants. Interestingly, NF plants showed no noticeable increase in oxidative metabolism, although they did show considerable increases in ascorbate peroxidase (APX) and peroxidase activities and transcript levels of APX, as in OF plants. Our results suggest that perturbations in carotenoid and porphyrin status by NF and OF can be sensed by differential photooxidative stress signaling, such as that involving H 2 O 2 , redox state of ascorbate and glutathione, and salicylic acid, which may be responsible for at least part of the induction of ROS-scavenging enzymes. Copyright © 2018 Elsevier Inc. All rights reserved.

Effects of nano-TiO2 -LDPE packaging on postharvest quality and antioxidant capacity of strawberry (Fragaria ananassa Duch.) stored at refrigeration temperature.

PubMed

Li, Dongdong; Ye, Qingyang; Jiang, Lei; Luo, Zisheng

2017-03-01

Nano-TiO 2 -low-density polyethylene (NTLDPE) packaging was prepared, and the effects of NTLDPE packaging on quality and antioxidant capacity of strawberry fruits were investigated. With increased barrier properties, NTLDPE packaging quickly formed a relative lower O 2 and higher CO 2 air composition in comparison with LDPE. It was also more efficient in maintaining the overall quality of strawberry fruit, as reflected by lower decay rate and weight loss, as well as retarding the decrease in firmness and titratable acid. Meanwhile, reactive oxygen species (ROS) including superoxide anion and hydrogen peroxide in NTLDPE-packed fruits were 10.8% and 21.9% lower, respectively. Furthermore, the activities of antioxidant enzymes involved in ROS scavenging in NTLDPE-packed fruits were significantly higher at the later period of storage time. Anthocyanin accumulation was inhibited, whereas ascorbic acid and total phenolics contents were better retained and 1-diphenyl-2-picrylhydrazyl radical scavenging activity was 13.2% higher in NTLDPE-packed fruit by the end of storage. These data indicate that the beneficial effects of NTLDPE packaging on postharvest quality and antioxidant capacity of strawberry are probably associated with the promotion of ROS scavenging and related antioxidant enzyme activities, and NTLDPE packaging together with refrigeration storage is a promising method for strawberry fruit preservation. © 2016 Society of Chemical Industry. © 2016 Society of Chemical Industry.

Supplementation of Ascorbic Acid in Weanling Horses Following Prolonged Transportation

PubMed Central

Ralston, Sarah; Stives, Michelle

2012-01-01

Simple Summary Horses normally synthesize adequate amounts of ascorbic acid (vitamin C) in their liver to meet their needs for the vitamin. However, prolonged stress results in low plasma concentrations and reduced immune function. Weanling horses were supplemented with ascorbic acid for 5 or 10 days or no ascorbic acid (4 per group) following 50+ hours of transportation. Supplementation caused increases in plasma concentrations but both supplemented groups had decreased plasma ascorbic acid for 1 to 3 weeks following cessation of supplementation, possibly due to suppressed synthesis. Supplementation of ascorbic acid following prolonged stress will increase plasma concentrations, but prolonged supplementation should be avoided. Abstract Though horses synthesize ascorbic acid in their liver in amounts that meet their needs under normal circumstances, prolonged stress results in low plasma concentrations due to enhanced utilization and renal excretion and can reduce immune function. It was hypothesized that plasma ascorbic acid could be maintained in weanling horses by oral supplementation following prolonged transportation. Weanlings were supplemented with no ascorbic acid (Tx 0: n = 4), 5 grams ascorbic acid twice daily for 5 days (Tx 1: n = 4) or for 10 days (Tx 2: n = 4) following >50 hours of transportation. Supplementation caused slight (P < 0.2) increases in plasma ascorbic acid concentrations. Both supplemented groups had decreased (P < 0.05) plasma concentrations for 1 to 3 weeks following cessation of supplementation, possibly due to increased renal excretion or suppressed hepatic synthesis. Supplementation of ascorbic acid following prolonged stress will increase plasma concentrations, but prolonged supplementation should be avoided. PMID:26486916

An in vitro model to test relative antioxidant potential: Ultraviolet-induced lipid peroxidation in liposomes

DOE Office of Scientific and Technical Information (OSTI.GOV)

Pelle, E.; Maes, D.; Padulo, G.A.

1990-12-01

Since antioxidants have been shown to play a major role in preventing some of the effects of aging and photoaging in skin, it is important to study this phenomenon in a controlled manner. This was accomplished by developing a simple and reliable in vitro technique to assay antioxidant efficacy. Inhibition of peroxidation by antioxidants was used as a measure of relative antioxidant potential. Liposomes, high in polyunsaturated fatty acids (PUFA), were dispersed in buffer and irradiated with ultraviolet (UV) light. Irradiated liposomes exhibited a significantly higher amount of hydroperoxides than liposomes containing antioxidants in a dose- and concentration-dependent manner. Lipidmore » peroxidation was determined spectrophotometrically by an increase in thiobarbituric acid reacting substances. To further substantiate the production of lipid peroxides, gas chromatography was used to measure a decrease in PUFA substrate. In order of decreasing antioxidant effectiveness, the following results were found among lipophilic antioxidants: BHA greater than catechin greater than BHT greater than alpha-tocopherol greater than chlorogenic acid. Among hydrophilic antioxidants, ascorbic acid and dithiothreitol were effective while glutathione was ineffective. In addition, ascorbic acid was observed to act synergistically with alpha-tocopherol, which is in agreement with other published reports on the interaction of these two antioxidants. Although peroxyl radical scavengers seem to be at a selective advantage in this liposomal/UV system, these results demonstrate the validity of this technique as an assay for measuring an antioxidant's potential to inhibit UV-induced peroxidation.« less

Changes in carotenoids, ascorbic acids, and quality characteristics by the pickling of paprika (Capsicum annuum l.) cultivated in Korea.

PubMed

Park, Jihyun; Kim, Suna; Moon, Bokyung

2011-09-01

Paprika (Capsicum annuum L.) is widely used as a healthy vegetable having antitumor-promoting activity and reducing or preventing chronic disease. Paprika has been mostly consumed as fresh fruit, and as food colorants such as oleoresin or pigment powder. In this study, pickled paprika was produced and its quality characteristics were monitored during storage (35 °C for 42 d). Carotenoid composition, ascorbic acid, total phenolic contents, and antioxidant activities were also analyzed. Five carotenoid compounds were identified in the pickled paprika and after 42 d of storage, total carotenoid content was 2.44 ± 0.69 mg/100g fresh weight(fw) and ascorbic acid content was 50.90 ± 3.26 mg/100g dry weight (dw). 2,2'-azino-di-(3-ethylbenzthiazoline sulphonate (ABTS) radical-scavenging activity of the pickled paprika was maintained above 70% until 28 d of storage, and then decreased to 47% of the initial activity. pH increased from 2.78 ± 0.06 to 3.10 ± 0.03 at 14 d and was then maintained until 42 d. Soluble solids increased gradually and color values including L*, a*, and b* decreased during storage. Hardness also decreased from 6.17 ± 0.18 kg force to 1.90 ± 0.60 kg force during storage. The overall taste of the pickled paprika was deemed to be good until 28 d of storage. Pickled paprika showed a possibility as a new pickled product. We demonstrated that paprika could be processed as a new pickled product with extended storage. Pickled paprika was produced and its quality characteristics along with phytochemical contents were monitored during storage. Phytochemicals, including ascorbic acid and polyphenols in pickled paprika were considerably retained and visual color was satisfactory during storage. Texture was deemed to be satisfactory for 4 wk. Considering that our experiment was performed at a relatively high temperature and without the addition of calcium for the improvement of texture, our results are quite promising in order to produce new pickled products with extended shelf-life along with conserving nutritional and functional components and satisfying consumer needs. © 2011 Institute of Food Technologists®

Ascorbic acid glucoside reduces neurotoxicity and glutathione depletion in mouse brain induced by nitrotriazole radiosensitazer.

PubMed

Cherdyntseva, Nadezda V; Ivanova, Anna A; Ivanov, Vladimir V; Cherdyntsev, Evgeny; Nair, Cherupally Krishnan Krishnan; Kagiya, Tsutomu V

2013-01-01

To investigate the potential of the anti-oxidant ascorbic acid glucoside (AA-2G) to modulate neurotoxicity induced by high doses of nitrotriazole radiosensitizer. Male and female C56Bl/6xCBA hybrid mice aged 8-14 weeks (weight 18-24 g) were used. Nitrotriazole drug radiosensitizer sanazole at a high dose of 2, 1 g/kg was per os administered to induce neurotoxicity at mice. Ascorbic acid glucoside was given 30 min before the sanazole administration. Serum ascorbic acid, brain glutathione level, as well as behavioral performance using open field apparatus were measured. Administration of high (non-therapeutic) doses of the nitrotriazole drug sanazole results in neurotoxicity in mice as evidenced from behavioral performance, emotional activity and depletion of the cellular antioxidant, glutathione, in the brain. The serum levels of ascorbic acid was also found reduced in high dose sanazole treated animals. Per os administration of ascorbic acid glucoside significantly reduced the neurotoxicity. This effect was associated with the prevention of glutathione depletion in mouse brain and restoring the ascorbic acid level in serum. Administration of ascorbic acid glucoside, but not ascorbic acid, before sanazole administration protected from sanazole-induced neurotoxicity by preventing the decrease in the brain reduced glutathione level and providing high level of ascorbic acid in plasma.

Electrochemical impedance based chiral analysis of anti-ascorbutic drug: l-Ascorbic acid and d-ascorbic acid using C-dots decorated conductive polymer nano-composite electrode.

PubMed

Pandey, Indu; Kant, Rama

2016-03-15

Clinical manifestations owing to l-ascorbic acid for scurvy as comparison to d-ascorbic acid and challenges of chiral purity are overcome by using chiral selective conductive polymer nanocomposite which mimics antibodies and enzymes. A novel chiral selective imprinted polyaniline-ferrocene-sulfonic acid film has been electrochemically fabricated on C-dots modified pencil graphite electrode. The performance of the obtained l-ascorbic acid or d-ascorbic acid chiral selective sensor was investigated by electrochemical impedance spectroscopy, cyclic and differential pulse voltammetry. The surface characteristics of the C-dots, chiral sensor before and after the de-doping of chiral d- and l-ascorbic acid were characterized by scanning electron microscopy, Raman spectroscopy and X-ray diffraction spectroscopy. Excellent recognition results were obtained by difference in electron transfer resistance. The proposed chiral sensor is capable of measuring d-ascorbic acid or l-ascorbic acid in aqueous as well as in real and commercial samples within the range of 0.020-0.187 nM and 0.003-0.232 nM with detection limit of 0.00073 nM and 0.00016 nM, respectively. The proposed method has also been examined for the chiral selective recognition of ascorbic acid isomers (d- and l-) quantitatively, in complicated matrices of real samples. Copyright © 2015 Elsevier B.V. All rights reserved.

Silver Nanoparticles Mediated by Costus afer Leaf Extract: Synthesis, Antibacterial, Antioxidant and Electrochemical Properties.

PubMed

Elemike, Elias E; Fayemi, Omolola E; Ekennia, Anthony C; Onwudiwe, Damian C; Ebenso, Eno E

2017-04-29

Synthesis of metallic and semiconductor nanoparticles through physical and chemical routes has been extensively reported. However, green synthesized metal nanoparticles are currently in the limelight due to the simplicity, cost-effectiveness and eco-friendliness of their synthesis. This study explored the use of aqueous leaf extract of Costus afer in the synthesis of silver nanoparticles (CA-AgNPs). The optical and structural properties of the resulting silver nanoparticles were studied using UV-visible spectroscopy, scanning electron microscopy (SEM), transmission electron microscopy (TEM) and Fourier transform infra-red spectrophotometer (FTIR). TEM images of the silver nanoparticles confirmed the existence of monodispersed spherical nanoparticles with a mean size of 20 nm. The FTIR spectra affirmed the presence of phytochemicals from the Costus afer leaf extract on the surface of the silver nanoparticles. The electrochemical characterization of a CA-AgNPs/multiwalled carbon nanotubes (MWCNT)-modified electrode was carried out to confirm the charge transfer properties of the nanocomposites. The comparative study showed that the CA-AgNPs/MWCNT-modified electrode demonstrated faster charge transport behaviour. The anodic current density of the electrodes in Fe(CN)₆] 4- /[Fe(CN)₆] 3- redox probe follows the order: GCE/CA-Ag/MWCNT (550 mA/cm²) > GCE/MWCNT (270 mA/cm²) > GCE (80 mA/cm²) > GCE/CA-Ag (7.93 mA/cm²). The silver nanoparticles were evaluated for their antibacterial properties against Gram negative ( Escherichia coli, Klebsiella pneumonia, Pseudomonas aeruginosa ) and Gram positive ( Bacillus subtilis and Staphylococcus aureus ) pathogens. The nanoparticles exhibited better inhibition of the bacterial strains compared to the precursors (leaf extract of Costus afer and silver nitrate). Furthermore, the ability of the nanoparticles to scavenge DPPH radicals at different concentrations was studied using the DPPH radical scavenging assay and compared to that of the leaf extract and ascorbic acid. The nanoparticles were better DPPH scavengers compared to the leaf extract and their antioxidant properties compared favorably the antioxidant results of ascorbic acid. The green approach to nanoparticles synthesis carried out in this research work is simple, non-polluting, inexpensive and non-hazardous.

Kinetic multi-layer model of the epithelial lining fluid (KM-ELF): Reactions of ozone and OH with antioxidants and surfactant molecules

NASA Astrophysics Data System (ADS)

Lakey, Pascale; Pöschl, Ulrich; Shiraiwa, Manabu

2015-04-01

Oxidants cause damage to biosurfaces such as the lung epithelium unless they are effectively scavenged. The respiratory tract is covered in a thin layer of fluid which extends from the nasal cavity to the alveoli and contain species that scavenge ozone and other incoming oxidants. The kinetic multi-layer model of the epithelial lining fluid (KM-ELF) has been developed in order to investigate the reactions of ozone and OH with antioxidants (ascorbate, uric acid, glutathione and α-tocopherol) and surfactant lipids and proteins within the epithelial lining fluid (ELF). The model incorporates different processes: gas phase diffusion, adsorption and desorption from the surface, bulk phase diffusion and known reactions at the surface and in the bulk. The ELF is split into many layers: a sorption layer, a surfactant layer, a near surface bulk layer and several bulk layers. Initial results using KM-ELF indicate that at ELF thicknesses of 80 nm and 1 × 10-4cm the ELF would become rapidly saturated with ozone with saturation occurring in less than a second. However, at an ELF thickness of 1 × 10-3cm concentration gradients were observed throughout the ELF and the presence of antioxidants reduced the O3 reaching the lung cells and tissues by 40% after 1 hour of exposure. In contrast, the antioxidants were efficient scavengers of OH radicals, although the large rate constants of OH reacting with the antioxidants resulted in the antioxidants decaying away rapidly. The chemical half-lives of the antioxidants and surface species were also calculated using KM-ELF as a function of O3 and OH concentration and ELF thickness. Finally, the pH dependence of the products of reactions between antioxidants and O3 were investigated. The KM-ELF model predicted that a harmful ascorbate ozonide product would increase from 1.4 × 1011cm-3at pH 7.4 to 1.1 × 1014 cm-3 at pH 4after 1 hour although a uric acid ozonide product would decrease from 2.0 × 1015cm-3to 5.9 × 1012cm-3.

Control of enzymatic browning in apple slices by using ascorbic acid under different conditions.

PubMed

el-Shimi, N M

1993-01-01

Control of phenol oxidase activity in apple slices by the use of ascorbic acid at different pH values, temperature and time of incubation was investigated. The enzyme was almost inactivated at 1% and 1.5% ascorbic acid. Ascorbic acid solution (1%) caused a remarkable inhibition with the increasing acidity up to pH = 1. Heating treatments for apple slices dipped in 1% ascorbic acid caused a reduction of enzymatic browning, optimum temperature for inactivation of the enzyme was between 60-70 degrees C for 15 minutes. Increasing the time of dipping apple slices in 1% ascorbic acid solutions and at different pH values reduce phenolase activity.

21 CFR 172.315 - Nicotinamide-ascorbic acid complex.

Code of Federal Regulations, 2011 CFR

2011-04-01

... 21 Food and Drugs 3 2011-04-01 2011-04-01 false Nicotinamide-ascorbic acid complex. 172.315... HUMAN CONSUMPTION Special Dietary and Nutritional Additives § 172.315 Nicotinamide-ascorbic acid complex. Nicotinamide-ascorbic acid complex may be safely used in accordance with the following prescribed conditions...

Comparison of bioactive components in pressurized and pasteurized longan juices fortified with encapsulated Lactobacillus casei 01

NASA Astrophysics Data System (ADS)

Chaikham, Pittaya; Apichartsrangkoon, Arunee

2012-06-01

In this study, longan juice was subjected to a high pressure of 500 MPa for 30 min and compared with a juice pasteurized at 90°C/2 min. Probiotic Lactobacillus casei 01 was fortified into both juices and the shelf life of these products was studied. Their bioactive components such as ascorbic acid, gallic acid and ellagic acid were analyzed by High Performance Liquid Chromatography (HPLC). Total phenolic compounds and 2,2-Diphenyl-1-picrythydrazyl radical-scavenging activity were determined by colorimetric and spectrophotometric methods. It was found that the pressurized longan juice retained higher amounts of bioactive compounds than the pasteurized juice. In terms of storage stability, bioactive compounds in both processed juices decreased according to the increase in storage time. The survivability of probiotic L. casei 01 in both processed juices declined from 9 to 6 log CFU/mL after 4 weeks of storage.

Effects of boiling and in vitro gastrointestinal digestion on the antioxidant activity of Sonchus oleraceus leaves.

PubMed

Mawalagedera, S M M R; Ou, Zong-Quan; McDowell, Arlene; Gould, Kevin S

2016-03-01

Leaves of Sonchus oleraceus L. are especially rich in phenolic compounds and have potent extractable antioxidants. However, it is not known how their antioxidant activity changes after cooking and gastrointestinal digestion. We recorded the profile of phenolics and their associated antioxidant activity in both raw and boiled S. oleraceus leaf extracts after in vitro gastric and intestinal digestion, and quantified their antioxidant potentials using Caco-2 and HepG2 cells. Boiling significantly diminished the oxygen radical absorbance capacity (ORAC) and concentrations of ascorbate and chicoric acid in the soluble fractions. In contrast, 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging and concentrations of caftaric and chlorogenic acids were unaffected. Phenolics in the soluble fraction were absorbed into cultured human cells and exerted antioxidant activity. Only chlorogenic acid content remained stable during gastrointestinal digestion. S. oleraceus appears to be an excellent dietary source of phenolic antioxidants.

Therapeutic review: is ascorbic acid of value in chromium poisoning and chromium dermatitis?

PubMed

Bradberry, S M; Vale, J A

1999-01-01

Repeated topical exposure to chromium(VI) may cause an allergic contact dermatitis or the formation of chrome ulcers. Systemic toxicity may occur following the ingestion of a chromium(VI) salt, from chromium(VI)-induced skin burns, or from inhalation of chromium(VI) occurring occupationally. Soluble chromium(VI) salts are usually absorbed more easily and cross cell membranes more readily than trivalent chromium salts, and, therefore chromium(VI) is more toxic than chromium(III). In experimental studies, endogenous ascorbic acid in rat lung, liver, and kidney and human plasma, effectively reduces chromium(VI) to chromium(III). The administration of exogenous ascorbic acid has been advocated therefore in the treatment of systemic chromium poisoning and chromium dermatitis to enhance the extracellular reduction of chromium(VI) to the less bioavailable chromium(III). In vitro experiments confirm that the addition of ascorbic acid to plasma containing chromium(VI) leads to a dose-dependent reduction of chromium(VI) to chromium(III). In animal studies, parenteral ascorbic acid 0.5-5 g/kg significantly reduced chromium-induced nephrotoxicity when administered 30 minutes before parenteral sodium dichromate and up to 1 hour after parenteral sodium chromate dosing. Parenteral ascorbic acid 0.5-5 g/kg also reduced mortality when given orally up to 2 hours after oral potassium dichromate dosing. However, the administration of parenteral ascorbic acid more than 2 hours after parenteral chromate in these experimental studies did not protect against renal damage, and parenteral ascorbic acid given 3 hours postparenteral chromate increased toxicity. In addition, there is no confirmed clinical evidence that the administration of ascorbic acid lessens morbidity or mortality in systemic chromium poisoning. A possible reason for the lack of benefit of ascorbic acid when administration is delayed, is that chromium(VI) cellular uptake has occurred prior to ascorbic acid administration. Topical 10% ascorbic acid has been claimed to reduce significantly the healing time of experimentally induced chrome ulcers in guinea pigs. The proposed mechanism is reduction on the skin surface of chromium(VI) to chromium(III). Several case reports suggest that topical ascorbic acid is effective in the management of chromium dermatitis but this has not been confirmed in controlled clinical trials and, moreover, the practical difficulties of frequent application are likely to limit its usefulness. Based on experimental studies, substantial amounts of ascorbic acid would need to be administered, preferably parenterally, soon after exposure to prevent systemic toxicity from chromium(VI) in humans. However, as ascorbic acid is a metabolic precursor of oxalate, the administration of ascorbic acid in high dose could lead to acute oxalate nephropathy, particularly in the presence of renal failure. While smaller doses of ascorbic acid (e.g., 10 g intravenously) are not toxic, such doses probably will not reduce the mortality from systemic chromium poisoning. There is currently insufficient evidence to advocate the use of ascorbic acid in the management of systemic chromium toxicity. Topical ascorbic acid may reduce dermal hexavalent chromium exposure, but this observation must be confirmed in controlled studies.

21 CFR 182.8013 - Ascorbic acid.

Code of Federal Regulations, 2014 CFR

2014-04-01

... 21 Food and Drugs 3 2014-04-01 2014-04-01 false Ascorbic acid. 182.8013 Section 182.8013 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) SUBSTANCES GENERALLY RECOGNIZED AS SAFE Nutrients § 182.8013 Ascorbic acid. (a) Product. Ascorbic acid. (b) Conditions...

21 CFR 582.3013 - Ascorbic acid.

Code of Federal Regulations, 2011 CFR

2011-04-01

... 21 Food and Drugs 6 2011-04-01 2011-04-01 false Ascorbic acid. 582.3013 Section 582.3013 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL DRUGS... Ascorbic acid. (a) Product. Ascorbic acid. (b) Conditions of use. This substance is generally recognized as...

The preparation and antioxidant activity of the sulfanilamide derivatives of chitosan and chitosan sulfates.

PubMed

Zhong, Zhimei; Ji, Xia; Xing, Ronge; Liu, Song; Guo, Zhanyong; Chen, Xiaolin; Li, Pengcheng

2007-06-01

Chitosan (CS) and chitosan sulfates (CSS) with different molecular weight (Mw) were reacted with 4-acetamidobenzene sulfonyl chloride to obtain sulfanilamide derivatives of chitosan and chitosan sulfates (LSACS, HSACS, LSACSS, HSACSS). The preparation conditions such as different reaction time, temperature, solvent, and the molar ratio of reaction materials are discussed in this paper. Their structures were characterized by FTIR spectroscopy and elemental analyses. The antioxidant activities of the derivatives were investigated employing various established in vitro systems, such as hydroxyl-radical ((*)OH) superoxide anion (O2(*-)) scavenging and reducing power. All kinds of the compounds (HCS, LCS, HCSS, LCSS, HSACS, LSACS, HSACSS, LSACSS) showed stronger scavenging activity on hydroxyl radical than ascorbic acid (Vc). The inhibitory activities of the derivatives toward superoxide radical by the PMS-NADH system were obvious. The experiment showed that the superoxide radical scavenging effect of sulfanilamide derivatives of chitosan and chitosan sulfates was stronger than that of original CS and CSS. All of the derivatives were efficient in the reducing power. The results indicated that the sulfanilamide group were grafted on CS and CSS increased the reducing power of them obviously.

Carbohydrase inhibition and anti-cancerous and free radical scavenging properties along with DNA and protein protection ability of methanolic root extracts of Rumex crispus

PubMed Central

Shiwani, Supriya; Singh, Naresh Kumar

2012-01-01

The study elucidated carbohydrase inhibition, anti-cancerous, free radical scavenging properties and also investigated the DNA and protein protection abilities of methanolic root extract of Rumex crispus (RERC). For this purpose, pulverized roots of Rumex crispus was extracted in methanol (80% and absolute conc.) for 3 hrs for 60℃ and filtered and evaporated with vacuum rotary evaporator. RERC showed high phenolic content (211 µg/GAE equivalent) and strong 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging (IC50 = 42.86 (absolute methanol) and 36.91 µg/mL (80% methanolic extract)) and reduced power ability. Furthermore, RERC exhibited significant protective ability in H2O2/Fe3+/ascorbic acid-induced protein or DNA damage and percentage inhibition of the HT-29 cell growth rate following 80% methanolic RERC exposure at 400 µg/mL was observed to be highest (10.2% ± 1.03). Moreover, methanolic RERC inhibited α-glucosidase and amylase effectively and significantly (P < 0.05). Conclusively, RERC could be considered as potent carbohydrase inhibitor, anti-cancerous and anti-oxidant. PMID:23198017

Oxygen radical absorbance capacity of phycocyanin and phycocyanobilin from the food supplement Aphanizomenon flos-aquae.

PubMed

Benedetti, Serena; Benvenuti, Francesca; Scoglio, Stefano; Canestrari, Franco

2010-02-01

The oxygen radical absorbance capacity (ORAC) assay has been widely used to quantify peroxyl radical scavenging capacity of pure antioxidant compounds and antioxidant plant/food extracts. However, it has never been applied to natural compounds derived from microalgae-based dietary supplements, namely, phycocyanin (PC) and phycocyanobilin (PCB), for which a strong radical scavenger activity has been documented. In this article, we applied the ORAC method to investigate the capacity of PC and PCB purified from the edible microalga Aphanizomenon flos-aquae to directly quench peroxyl radicals in comparison to well-known antioxidants molecules such as Trolox, ascorbic acid, and reduced glutathione. As a result, PCB was found to have the highest ORAC value (22.18 micromol of Trolox/micromol of compound), comparable to that of PC (20.33 micromol of Trolox/micromol of compound), hence confirming that PCB is mostly responsible for the scavenger activity of PC and making the protein a possible source of the antioxidant in vivo. Our data further corroborate the use of these natural compounds from A. flos-aquae as dietary antioxidant supplements in the treatment of clinical conditions related to oxidative stress.

In vitro radical scavenging activity of two Columbian Magnoliaceae

NASA Astrophysics Data System (ADS)

Puertas M., Miguel A.; Mesa v., Ana M.; Sáez v., Jairo A.

2005-08-01

The recent interest in the conservation of the tropical forest is due, at least in part, to the potential economic and health benefits that can be exploited from several plants. This report shows the in vitro antioxidant activity of some fractions isolated from leaves of two Columbian Magnoliaceae, Talauma hernandezii G. Lozano-C and Dugandiodendron yarumalense Lozano. The activity was determined using the radical monocation 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS·+) and the stable free radical 2-2-diphenyl-1-picrylhydrazyl (DPPH·), as part of general biological screening of these plants. The antioxidant capacity obtained from fractions was similar to those of α-tocopherol, tert-butylated hydroxyanisole (BHA), and ascorbic acid. The most active scavenger extract was the fraction 7 (TAA = 48.6 mmol Trolox/kg extract and IC50 ≤ 0.01 kg extract/mmol DPPH); and the least active was the fraction 1 (TAA = 11.23 mmol Trolox/kg extract and IC50 = 0.21 kg extract/mmol DPPH) all of them isolated from D. yarumalense. These results suggest that these plants can be attractive as source of antioxidant compounds with the ability to reduce radicals like ATBS and DPPH.

Determination of antioxidant activity of Hibiscus sabdariffa and Croton caudatus in Saccharomyces cerevisiae model system.

PubMed

Subhaswaraj, Pattnaik; Sowmya, M; Bhavana, V; Dyavaiah, Madhu; Siddhardha, Busi

2017-08-01

From ancient times, plants and plant derived products are exploited as a prominent source of folkloric medicines with tremendous therapeutic potential for an array of health disorders. In the present study, ethanolic leaf extract of Hibiscus sabdariffa and Croton caudatus were evaluated for free radical scavenging activity in Saccharomyces cerevisiae model system. H. sabdariffa and C. caudatus showed tremendous DPPH free radical scavenging potential with an IC 50 value of 184.88 and 305.39 µg/mL respectively at a concentration of 500 µg/mL. The ethanolic leaf extract of H. sabdariffa and C. caudatus also showed significant hydoxyl radical scavenging and total antioxidant activity. Ascorbic acid was used as positive control. The in vitro antioxidant activity was further supported by in vivo studies using radical scavenging mechanism in S. cerevisiae wild type and its isogenic deletion strains sod1∆ and tsa1∆ . The mutant yeast cells substantially scavenged the stress generated by H 2 O 2 when supplemented with ethanolic leaf extract of H. sabdariffa and C. caudatus as evident from spot assays followed by fluorescence assay (DCF-DA) using fluorescence microscopic and intensity studies. H. sabdariffa and C.caudatus significantly neutralize the ROS level in yeast mutants with concomitant decrease in fluorescence intensity as compared to the untreated yeast cells. The results suggested the efficacy of H. sabdariffa and C. caudatus as potent antioxidants in yeast system and thus their futuristic applications in therapeutics.

A structural basis for the pH-dependent xanthophyll cycle in Arabidopsis thaliana.

PubMed

Arnoux, Pascal; Morosinotto, Tomas; Saga, Giorgia; Bassi, Roberto; Pignol, David

2009-07-01

Plants adjust their photosynthetic activity to changing light conditions. A central regulation of photosynthesis depends on the xanthophyll cycle, in which the carotenoid violaxanthin is converted into zeaxanthin in strong light, thus activating the dissipation of the excess absorbed energy as heat and the scavenging of reactive oxygen species. Violaxanthin deepoxidase (VDE), the enzyme responsible for zeaxanthin synthesis, is activated by the acidification of the thylakoid lumen when photosynthetic electron transport exceeds the capacity of assimilatory reactions: at neutral pH, VDE is a soluble and inactive enzyme, whereas at acidic pH, it attaches to the thylakoid membrane where it binds its violaxanthin substrate. VDE also uses ascorbate as a cosubstrate with a pH-dependent Km that may reflect a preference for ascorbic acid. We determined the structures of the central lipocalin domain of VDE (VDEcd) at acidic and neutral pH. At neutral pH, VDEcd is monomeric with its active site occluded within a lipocalin barrel. Upon acidification, the barrel opens up and the enzyme appears as a dimer. A channel linking the two active sites of the dimer can harbor the entire carotenoid substrate and thus may permit the parallel deepoxidation of the two violaxanthin beta-ionone rings, making VDE an elegant example of the adaptation of an asymmetric enzyme to its symmetric substrate.

A Structural Basis for the pH-Dependent Xanthophyll Cycle in Arabidopsis thaliana[C][W

PubMed Central

Arnoux, Pascal; Morosinotto, Tomas; Saga, Giorgia; Bassi, Roberto; Pignol, David

2009-01-01

Plants adjust their photosynthetic activity to changing light conditions. A central regulation of photosynthesis depends on the xanthophyll cycle, in which the carotenoid violaxanthin is converted into zeaxanthin in strong light, thus activating the dissipation of the excess absorbed energy as heat and the scavenging of reactive oxygen species. Violaxanthin deepoxidase (VDE), the enzyme responsible for zeaxanthin synthesis, is activated by the acidification of the thylakoid lumen when photosynthetic electron transport exceeds the capacity of assimilatory reactions: at neutral pH, VDE is a soluble and inactive enzyme, whereas at acidic pH, it attaches to the thylakoid membrane where it binds its violaxanthin substrate. VDE also uses ascorbate as a cosubstrate with a pH-dependent Km that may reflect a preference for ascorbic acid. We determined the structures of the central lipocalin domain of VDE (VDEcd) at acidic and neutral pH. At neutral pH, VDEcd is monomeric with its active site occluded within a lipocalin barrel. Upon acidification, the barrel opens up and the enzyme appears as a dimer. A channel linking the two active sites of the dimer can harbor the entire carotenoid substrate and thus may permit the parallel deepoxidation of the two violaxanthin β-ionone rings, making VDE an elegant example of the adaptation of an asymmetric enzyme to its symmetric substrate. PMID:19638474

Alteration of chemical behavior of L-ascorbic acid in combination with nickel sulfate at different pH solutions in vitro

PubMed Central

Maniyar, Shaheen A; Jargar, Jameel G; Das, Swastika N; Dhundasi, Salim A; Das, Kusal K

2012-01-01

Objective To evaluate the alteration of chemical behavior of L-ascorbic acid (vitamin C) with metal ion (nickel) at different pH solutions in vitro. Methods Spectra of pure aqueous solution of L-ascorbic acid (E mark) compound and NiSO4 (H2O) (sigma USA) were evaluated by UV visible spectrophotometer. Spectral analysis of L-ascorbic acid and nickel at various pH (2.0, 7.0, 7.4 and 8.6) at room temperature of 29 °C was recorded. In this special analysis, combined solution of L-ascorbic acid and nickel sulfate at different pH was also recorded. Results The result revealed that λmax (peak wavelength of spectra) of L-ascorbic acid at pH 2.0 was 289.0 nm whereas at neutral pH 7.0, λmax was 295.4 nm. In alkaline pH 8.6, λmax was 295.4 nm and at pH 7.4 the λmax of L-ascorbic acid remained the same as 295.4 nm. Nickel solution at acidic pH 2.0 was 394.5 nm, whereas at neutral pH 7.0 and pH 7.4 were the same as 394.5 nm. But at alkaline pH 8.6, λmax value of nickel sulfate became 392.0 nm. The combined solution of L-ascorbic acid and nickel sulfate (6 mg/mL each) at pH 2.0 showed 292.5 nm and 392.5 nm, respectively whereas at pH 7.0, L-ascorbic acid showed 296.5 nm and nickel sulfate showed 391.5 nm. At pH 7.4, L-ascorbic acid showed 297.0 nm and nickel sulfate showed 394.0 nm in the combined solution whereas at pH 8.6 (alkaline) L-ascorbic acid and nickel sulfate were showing 297.0 and 393.5 nm, respectively. Conclusions Results clearly indicate an altered chemical behavior of L-ascorbic acid either alone or in combination with nickel sulfate in vitro at different pH. Perhaps oxidation of L-ascorbic acid to L-dehydro ascorbic acid via the free radical (HSc*) generation from the reaction of H2ASc + Ni (II) is the cause of such alteration of λmax value of L-ascorbic acid in the presence of metal nickel. PMID:23569901

Effect of ascorbic acid on the stability of beta-carotene and capsanthin in paprika (Capsicum annuum) powder.

PubMed

Morais, H; Rodrigues, P; Ramos, C; Forgács, E; Cserháti, T; Oliveira, J

2002-10-01

The effect of ascorbic acid, light, and storage on the stability of the pigments beta-carotene and capsanthin in red pepper (Capsicum annuum) powder has been elucidated by determining the amount of pigment in samples treated by various concentrations of ascorbic acid. Determination of pigment concentration has been performed after different storage times using high-performance liquid chromatography. The dependence of the concentration of pigments on the concentration of ascorbic acid, presence of light and the storage time has been assessed by stepwise regression analysis. The concentration of pigments decreased at longer storage time and increased at higher concentration of ascorbic acid, beta-carotene being more sensitive towards storage time and concentration of ascorbic acid than capsanthin. Interaction between the effects of light and storage time, and light and concentration of ascorbic acid has been established.

The preparation and the sustained release of titanium dioxide hollow particles encapsulating L-ascorbic acid

NASA Astrophysics Data System (ADS)

Tominaga, Yoko; Kadota, Kazunori; Shimosaka, Atsuko; Yoshida, Mikio; Oshima, Kotaro; Shirakawa, Yoshiyuki

2018-05-01

The preparation of the titanium dioxide hollow particles encapsulating L-ascorbic acid via sol-gel process using inkjet nozzle has been performed, and the sustained release and the effect protecting against degradation of L-ascorbic acid in the particles were investigated. The morphology of titanium dioxide particles was evaluated by scanning electron microscopy (SEM) and energy dispersive X-ray spectrometry (EDS). The sustained release and the effect protecting against degradation of L-ascorbic acid were estimated by dialysis bag method in phosphate buffer saline (PBS) (pH = 7.4) as release media. The prepared titanium dioxide particles exhibited spherical porous structures. The particle size distribution of the titanium dioxide particles was uniform. The hollow titanium dioxide particles encapsulating L-ascorbic acid showed the sustained release. It was also found that the degradation of L-ascorbic acid could be inhibited by encapsulating L-ascorbic acid in the titanium dioxide hollow particles.

Interference of ascorbic acid with chemical analytes.

PubMed

Meng, Qing H; Irwin, William C; Fesser, Jennifer; Massey, K Lorne

2005-11-01

Ascorbic acid can interfere with methodologies involving redox reactions, while comprehensive studies on main chemistry analysers have not been reported. We therefore attempted to determine the interference of ascorbic acid with analytes on the Beckman Synchron LX20. Various concentrations of ascorbic acid were added to serum, and the serum analytes were measured on the LX20. With a serum ascorbic acid concentration of 12.0 mmol/L, the values for sodium, potassium, calcium and creatinine increased by 43%, 58%, 103% and 26%, respectively (P<0.01). With a serum ascorbic acid concentration of 12.0 mmol/L, the values for chloride, total bilirubin and uric acid decreased by 33%, 62% and 83%, respectively (P<0.01), and were undetectable for total cholesterol, triglyceride, ammonia and lactate. There was no definite influence of ascorbic acid on analytical values for total CO(2), urea, glucose, phosphate, total protein, albumin, amylase, creatine kinase, creatine kinase-MB, aspartate aminotransferase, alanine aminotransferase, alkaline phosphatase, total iron, unbound iron-binding capacity or magnesium. Ascorbic acid causes a false increase in sodium, potassium, calcium and creatinine results and a false decrease in chloride, total bilirubin, uric acid, total cholesterol, triglyceride, ammonia and lactate results.

Functional roles of flavonoids in photoprotection: new evidence, lessons from the past.

PubMed

Agati, Giovanni; Brunetti, Cecilia; Di Ferdinando, Martina; Ferrini, Francesco; Pollastri, Susanna; Tattini, Massimiliano

2013-11-01

We discuss on the relative significance of different functional roles potentially served by flavonoids in photoprotection, with special emphasis to their ability to scavenge reactive oxygen species (ROS) and control the development of individual organs and whole plant. We propose a model in which chloroplast-located flavonoids scavenge H2O2 and singlet oxygen generated under excess light-stress, thus avoiding programmed cell death. We also draw a picture in which vacuolar flavonoids in conjunction with peroxidases and ascorbic acid constitute a secondary antioxidant system aimed at detoxifying H2O2, which may diffuse out of the chloroplast at considerable rates and enter the vacuole following excess light stress-induced depletion of ascorbate peroxidase. We hypothesize for flavonols key roles as developmental regulators in early and current-day land-plants, based on their ability to modulate auxin movement and auxin catabolism. We show that antioxidant flavonoids display the greatest capacity to regulate key steps of cell growth and differentiation in eukaryotes. These regulatory functions of flavonoids, which are shared by plants and animals, are fully accomplished in the nM concentration range, as likely occurred in early land plants. We therefore conclude that functions of flavonoids as antioxidants and/or developmental regulators flavonoids are of great value in photoprotection. We also suggest that UV-B screening was just one of the multiple functions served by flavonoids when early land-plants faced an abrupt increase in sunlight irradiance. Copyright © 2013 Elsevier Masson SAS. All rights reserved.

Mechanism of ascorbic acid interference in biochemical tests that use peroxide and peroxidase to generate chromophore.

PubMed

Martinello, Flávia; Luiz da Silva, Edson

2006-11-01

Ascorbic acid interferes negatively in peroxidase-based tests (Trinder method). However, the precise mechanism remains unclear for tests that use peroxide, a phenolic compound and 4-aminophenazone (4-AP). We determined the chemical mechanism of this interference, by examining the effects of ascorbic acid in the reaction kinetics of the production and reduction of the oxidized chromophore in urate, cholesterol, triglyceride and glucose tests. Reaction of ascorbic acid with the Trinder method constituents was also verified. Ascorbic acid interfered stoichiometrically with all tests studied. However, it had two distinct effects on the reaction rate. In the urate test, ascorbic acid decreased the chromophore formation with no change in its production kinetics. In contrast, in cholesterol, triglyceride and glucose tests, an increase in the lag phase of color development occurred. Of all the Trinder constituents, only peroxide reverted the interference. In addition, ascorbic acid did not interfere with oxidase activity nor reduce significantly the chromophore formed. Peroxide depletion was the predominant chemical mechanism of ascorbic acid interference in the Trinder method with phenolics and 4-AP. Distinctive effects of ascorbic acid on the reaction kinetics of urate, cholesterol, glucose and triglyceride might be due to the rate of peroxide production by oxidases.

Enhancing antioxidant activity, microbial and sensory quality of mango (Mangifera indica L.) juice by γ-irradiation and its in vitro radioprotective potential.

PubMed

Naresh, Kondapalli; Varakumar, Sadineni; Variyar, Prasad Shekhar; Sharma, Arun; Reddy, Obulam Vijaya Sarathi

2015-07-01

Gamma irradiation is an effective method currently being used for microbial decontamination and insect disinfestations of foods. In the present study, mango (Mangifera indica L.) juice was irradiated at doses of 0, 1.0, 3.0 and 5.0 kGy and microbial load, total polyphenols, flavonoids, ascorbic acid content, antioxidant activities, colour and sensory properties were evaluated immediately after irradiation and also during storage. Microbiological assay of the fresh and stored mango juice showed better quality after γ-irradiation. The total polyphenols and flavonoids were significantly (p < 0.05) increased while the ascorbic acid content decreased with the irradiation doses applied. As a result of γ-irradiation, a significant increment in gallic, syringic and chlorogenic acids and a significant reduction in ferulic and synapic acids were noted when analyzed by HPLC. In vitro antioxidant potentials were measured using DPPH, FRAP and NO scavenging assays; the results showed significant enhancement in the activities after irradiation, that correlated well with the increase in phenolic and flavonoid content. γ-irradiation improved the colour of mango juice without any adverse changes in the sensory qualities. Significant in vitro plasmid DNA protection was observed in the presence of mango juice against radiation induced damage, even at the dose of 5 kGy. This study confirmed the potential of γ-irradiation as a method for microbial decontamination and improving the quality of the mango juice without compromising on the sensory attributes.

Structural Requirements of Alkylglyceryl-l-Ascorbic Acid Derivatives for Melanogenesis Inhibitory Activity.

PubMed

Taira, Norihisa; Katsuyama, Yushi; Yoshioka, Masato; Muraoka, Osamu; Morikawa, Toshio

2018-04-10

l-Ascorbic acid has multifunctional benefits on skin aesthetics, including inhibition of melanin production, and is widely used in cosmetics. It, however, has low stability and poor skin penetration. We hypothesize that alkylglyceryl-l-ascorbic acid derivatives, highly stable vitamin C-alkylglycerol conjugates, would have similar anti-melanogenic activity with better stability and penetration. We test 28 alkylglyceryl-l-ascorbic acid derivatives ( 1 - 28 ) on theophylline-stimulated B16 melanoma 4A5 cells to determine if they inhibit melanogenesis and establish any structure-function relationships. Although not the most potent inhibitors, 3- O -(2,3-dihydroxypropyl)-2- O -hexyl-l-ascorbic acid ( 6 , IC 50 = 81.4 µM) and 2- O -(2,3-dihydroxypropyl)-3- O -hexyl-l-ascorbic acid ( 20 , IC 50 = 117 µM) are deemed the best candidate derivatives based on their inhibitory activities and low toxicities. These derivatives are also found to be more stable than l-ascorbic acid and to have favorable characteristics for skin penetration. The following structural requirements for inhibitory activity of alkylglyceryl-l-ascorbic acid derivatives are also determined: (i) alkylation of glyceryl-l-ascorbic acid is essential for inhibitory activity; (ii) the 3- O -alkyl-derivatives ( 2 - 14 ) exhibit stronger inhibitory activity than the corresponding 2- O -alkyl-derivatives ( 16 - 28 ); and (iii) derivatives with longer alkyl chains have stronger inhibitory activities. Mechanistically, our studies suggest that l-ascorbic acid derivatives exert their effects by suppressing the mRNA expression of tyrosinase and tyrosine-related protein-1.

Free Radical Scavenging Properties of Annona squamosa

PubMed

Vikas, Biba; Akhil B, S; P, Remani; Sujathan, K

2017-10-26

Annona squamosa has extensively been used in the traditional and folkloric medicine and found to possess many biological activities. Different solvents, petroleum ether, chloroform, ethyl acetate and methanol extracts of Annona squamosa seeds (ASPE, ASCH, ASEA, ASME) have been used to prepare plant extracts. The present investigations dealt with the free radical scavenging activity of four extracts using various techniques such as total reducing power estimation, total phenolic count, 1,1-diphenyl-2-picryl hydrazyl (DPPH) radical scavenging effect, evaluation of ABTS cation decolorisation capacity, FRAP assay, hdroxyl radical scavenging assay, super oxide assay and Nitric oxide radical scavenging assay of the extracts. The results showed that the four extracts of Annona squamosa showed significant reducing power in four extracts. The total phenolic contents in petroleum ether, chloroform, ethyl acetate, methanol extracts and positive control were 0.64±0.17, 0.54±0.27, 0.49±0.24, 0.57±0.22 and 0.66±0.33. The antioxidant capacity by ABTS assay of ASPE, ASCH, ASEA, ASME and positive control, trolox showed 77.75±0.5,73.25±1.7,78.5± 1.2 , 80 ± 0.8 μg/ml and 94.2 ± 0.9 respectively. The (50 % scavenging activity) SA50 of ASPE and ASCH, ASEA and ASME was found to be 34.4 μg/ml, 43.8 μg/ml 34.7 μg/m and 28.8 μg/ml respectively by DPPH assay. The percentage of hydroxyl radical scavenging increased with the increasing concentration of the extracts. ASPE, ASCH, ASEA and ASME showed superoxide radical scavenging activity, as indicated by their values 66 ± 0.5, 68 ± 1 ,63 ± 1 and 70 ± 0.5 μg/ml respectively compared to gallic acid which was 97 ± 0.5 μg/ml. The values for scavenging of nitric oxide for ASPE, ASCH, ASEA and ASME were 91.0 ± 1.0, 66.75 ± 0.5, 71.75 ± 1.1 and 75.75 ± 1.15 μg/ml while value for standard ascorbic acid was 91.0 ± 1.0 μg/ml. The results revealed strong antioxidants in four extracts may lead to the development of potent antioxidant agents from Annona squamosa seeds. Creative Commons Attribution License

Ascorbic acid and melatonin reduce heat-induced performance inhibition and oxidative stress in Japanese quails.

PubMed

Sahin, N; Onderci, M; Sahin, K; Gursu, M F; Smith, M O

2004-02-01

1. The effects of ascorbic acid (L-ascorbic acid) and melatonin supplementation on performance, carcase characteristics, malondialdehyde (MDA) as lipid peroxidation indicator, ascorbic acid, retinol, tocopherol and mineral status in the Japanese quail (Coturnix coturnix japonica) exposed to high ambient temperature were evaluated. 2. Two hundred and forty Japanese quails (10 d old) were randomly assigned to 8 treatment groups consisting of 10 replicates of three birds each. The birds were kept in a temperature-controlled room at 22 degrees C (Thermoneutral, TN groups) or 34 degrees C (for 8 h/d; 09:00 to 17:00 h; Heat stress, HS groups). Birds in both TN and HS were fed either a basal (control) diet or the basal diet supplemented with 250 mg of L-ascorbic acid/kg of diet (Ascorbic acid group), 40 mg of melatonin/kg of diet (Melatonin group) or both (Ascorbic acid + Melatonin group). 3. Supplementing heat-stressed quails with ascorbic acid and melatonin improved performance compared with the control group. Effects generally were greatest in quails supplemented with both ascorbic acid and melatonin. 4. Although supplementation did not consistently restore the concentrations of serum ascorbic acid, retinol and tocopherol to those of TN groups, these concentrations increased significantly with supplementation. Furthermore, serum and liver MDA and serum cholesterol and glucose concentrations were lower in the supplemented groups than in the heat-stressed controls. 5. Within each environment, excretion of Ca, P, Mg, Zn, Fe and Cr were lowest in the combination group and, in all cases, highest in the HS group. Interactions between diet and temperature were detected for live weight gain, cold carcase weight, MDA, ascorbic acid, tocopherol concentrations and excretion of zinc. 6. The results of the study indicate that ascorbic acid and melatonin supplementation attenuate the decline in performance and antioxidant and mineral status caused by heat stress and such supplementation may offer protection against heat-stress-related depression in performance of Japanese quails.

Molecular Characterization and Antioxidant Potential of Three Wild Culinary-Medicinal Mushrooms from Tripura, Northeast India.

PubMed

Das, Aparajita Roy; Borthakur, Madhusmita; Saha, Ajay Krishna; Joshi, Santa Ram; Das, Panna

2017-01-01

The aim of this study was to characterize 3 wild culinary-medicinal mushrooms using molecular tools and to analyze their antioxidant activity. Antioxidant properties were studied by evaluating free radical scavenging, reducing power, and chelating effect. The mushrooms were identified as Lentinus squarrosulus, L. tuber-regium, and Macrocybe gigantean by amplifying internal transcribed spacer regions of ribosomal DNA. The results demonstrated that the methanolic extract of M. gigantean has the highest free radical scavenging effect and chelating effect, whereas the methanolic extract of L. squarrosulus has the highest reducing power. The highest total phenol content and the most ascorbic acid were found in the M. gigantean extracts. Among the 3 mushroom extracts, M. gigantean displayed the most potent antioxidant activity. Molecular characterization using the nuclear ribosomal internal transcribed spacer region as a universal DNA marker was an effective tool in the identification and phylogenetic analysis of the studied mushrooms. The study also indicated that these wild macrofungi are rich sources of natural antioxidants.

Attenuation of abnormalities in the lipid metabolism during experimental myocardial infarction induced by isoproterenol in rats: beneficial effect of ferulic acid and ascorbic acid.

PubMed

Yogeeta, Surinder Kumar; Hanumantra, Rao Balaji Raghavendran; Gnanapragasam, Arunachalam; Senthilkumar, Subramanian; Subhashini, Rajakannu; Devaki, Thiruvengadam

2006-05-01

The present study aims at evaluating the effect of the combination of ferulic acid and ascorbic acid on isoproterenol-induced abnormalities in lipid metabolism. The rats were divided into eight groups: Control, isoproterenol, ferulic acid alone, ascorbic acid alone, ferulic acid+ascorbic acid, ferulic acid+isoproterenol, ascorbic acid+isoproterenol and ferulic acid+ascorbic acid+isoproterenol. Ferulic acid (20 mg/kg b.w.t.) and ascorbic acid (80 mg/kg b.w.t.) both alone and in combination was administered orally for 6 days and on the fifth and the sixth day, isoproterenol (150 mg/kg b.w.t.) was injected intraperitoneally to induce myocardial injury to rats. Induction of rats with isoproterenol resulted in a significant increase in the levels of triglycerides, total cholesterol, free fatty acids, free and ester cholesterol in both serum and cardiac tissue. A rise in the levels of phospholipids, lipid peroxides, low density lipoprotein and very low density lipoprotein-cholesterol was also observed in the serum of isoproterenol-intoxicated rats. Further, a decrease in the level of high density lipoprotein in serum and in the phospholipid levels, in the heart of isoproterenol-intoxicated rats was observed, which was paralleled by abnormal activities of lipid metabolizing enzymes: total lipase, cholesterol ester synthase, lipoprotein lipase and lecithin: cholesterol acyl transferase. Pre-cotreatment with the combination of ferulic acid and ascorbic acid significantly attenuated these alterations and restored the levels to near normal when compared to individual treatment groups. Histopathological observations were also in correlation with the biochemical parameters. These findings indicate the synergistic protective effect of ferulic acid and ascorbic acid on isoproterenol-induced abnormalities in lipid metabolism.

Role of ascorbic acid in stratum corneum lipid models exposed to UV irradiation.

PubMed

Trommer, Hagen; Böttcher, Roif; Pöppl, Andreas; Hoentsch, Joachim; Wartewig, Siegfried; Neubert, Reinhard H H

2002-07-01

The effects of ascorbic acid on Stratum corneum lipid models following ultraviolet irradiation were studied adding iron ions as transition metal catalysts. Lipid peroxidation was quantified by the thiobarbituric acid assay. The qualitative changes were studied on a molecular level by mass spectrometry. To elucidate the nature of free radical involvement we carried out electron paramagnetic resonance studies. The influence of ascorbic acid on the concentration of hydroxyl radicals was examined using the spin trapping technique. Moreover, we checked the vitamin's ability to react with stable radicals. Ascorbic acid was found to have prooxidative effects in all lipid systems in a concentration dependent manner. The degradation products of ascorbic acid after its prooxidative action were detected. The concentration of the hydroxyl radicals in the Fenton assay was decreased by ascorbic acid. The quantification assay of 2,2-diphenyl-1-picrylhydrazyl hydrate showed reduced concentration levels of the stable radical caused by ascorbic acid. Considering human skin and its constant exposure to UV light and oxygen, an increased pool of iron ions in irradiated skin and the depletion of co-antioxidants, the administration of ascorbic acid in cosmetic formulations or in sunscreens could unfold adverse effects among the Stratum corneum lipids.

Chemical Transport Knockout for Oxidized Vitamin C, Dehydroascorbic Acid, Reveals Its Functions in vivo.

PubMed

Tu, Hongbin; Wang, Yu; Li, Hongyan; Brinster, Lauren R; Levine, Mark

2017-09-01

Despite its transport by glucose transporters (GLUTs) in vitro, it is unknown whether dehydroascorbic acid (oxidized vitamin C, DHA) has any in vivo function. To investigate, we created a chemical transport knockout model using the vitamin C analog 6-bromo-ascorbate. This analog is transported on sodium-dependent vitamin C transporters but its oxidized form, 6-bromo-dehydroascorbic acid, is not transported by GLUTs. Mice (gulo -/- ) unable to synthesize ascorbate (vitamin C) were raised on 6-bromo-ascorbate. Despite normal survival, centrifugation of blood produced hemolysis secondary to near absence of red blood cell (RBC) ascorbate/6-bromo-ascorbate. Key findings with clinical implications were that RBCs in vitro transported dehydroascorbic acid but not bromo-dehydroascorbic acid; RBC ascorbate in vivo was obtained only via DHA transport; ascorbate via DHA transport in vivo was necessary for RBC structural integrity; and internal RBC ascorbate was essential to maintain ascorbate plasma concentrations in vitro/in vivo. Published by Elsevier B.V.

Regulation of embryonic neurotransmitter and tyrosine hydroxylase protein levels by ascorbic acid

PubMed Central

Meredith, M. Elizabeth; May, James M.

2013-01-01

Scope: Ascorbic acid (ascorbate) is required to recycle tetrahydrobiopterin, which is necessary for neurotransmitter synthesis by the rate-limiting enzymes tyrosine and tryptophan hydroxylases. We sought to determine whether ascorbate might regulate embryonic brain cortex monoamine synthesis utilizing transgenic mouse models with varying intracellular ascorbate levels. Methods and Results: In embryos lacking the sodium-dependent vitamin C transporter 2 (SVCT2), very low levels of brain ascorbate decreased cortex levels of norepinephrine and dopamine by approximately 33%, but had no effect on cortex serotonin or its metabolite, 5-hydroxyindole acetic acid. This decrease in ascorbate also led to a decrease in protein levels of tyrosine hydroxylase, but not of tryptophan hydroxylase. Increased cortex ascorbate in embryos carrying extra copies of the SVCT2 resulted in increased levels of dopamine and its metabolite, 3,4-dihydroxyphenylacetic acid (DOPAC), as well as serotonin and 5-hydroxyindole acetic acid. Conclusion: The dependence of embryonic brain cortex neurotransmitter synthesis and tyrosine hydroxylase expression on intracellular ascorbate emphasizes the importance of receiving adequate ascorbate during development. PMID:24095796

Antioxidant, lipid peroxidation inhibition and free radical scavenging efficacy of a diterpenoid compound sugiol isolated from Metasequoia glyptostroboides.

PubMed

Bajpai, Vivek K; Sharma, Ajay; Kang, Sun Chul; Baek, Kwang-Hyun

2014-01-01

To investigate the antioxidant efficacy of a biologically active diterpenoid compound sugiol isolated from Metasequoia glyptostroboides (M. glyptostroboides) in various antioxidant models. An abietane type diterpenoid sugiol, isolated from ethyl acetate extract of M. glyptostroboides cones, was analyzed for its antioxidant efficacy as reducing power ability and lipid peroxidation inhibition as well as its ability to scavenge free radicals such as 1,1-diphenyl-2-picryl hydrazyl, nitric oxide, superoxide and hydroxyl radicals. The sugiol showed significant and concentration-dependent antioxidant and free radical scavenging activities. Consequently, the sugiol exerted lipid peroxidation inhibitory effect by 76.5% as compared to α-tocopherol (80.13%) and butylated hydroxyanisole (76.59%). In addition, the sugiol had significant scavenging activities of 1,1-diphenyl-2-picryl hydrazyl, nitric oxide, superoxide and hydroxyl free radicals in a concentration-dependent manner by 78.83%, 72.42%, 72.99% and 85.04%, when compared to the standard compound ascorbic acid (81.69%, 74.62%, 73.00% and 73.79%) and α-tocopherol/butylated hydroxyanisole (84.09%, 78.61%, 74.45% and 70.02%), respectively. These findings justify the biological and traditional uses of M. glyptostroboides or its secondary metabolites as confirmed by its promising antioxidant efficacy. Copyright © 2014 Hainan Medical College. Published by Elsevier B.V. All rights reserved.

Understanding the degradation of ascorbic acid and glutathione in relation to the levels of oxidative stress biomarkers in broccoli (Brassica oleracea L. italica cv. Bellstar) during storage and mechanical processing.

PubMed

Raseetha, Siva; Leong, Sze Ying; Burritt, David John; Oey, Indrawati

2013-06-01

The purpose of this research was to understand the degradation of ascorbic acid and glutathione content in broccoli florets (Brassica oleracea L. italica cv. Bellstar) during prolonged storage and subsequent mechanical processing. The initial content of total ascorbic acid and glutathione in broccoli florets averaged at 5.18 ± 0.23 and 0.70 ± 0.03 μmol/g fresh weight, respectively. Results showed that the content of ascorbic acid and glutathione in broccoli degraded during storage at 23°C, for at least 4.5-fold after 6 days of storage. On each day of storage, broccoli florets were mechanically processed, but the content of total ascorbic acid and glutathione was not significantly affected. When the mechanically processed broccoli florets were further incubated for up to 6h, the amount of ascorbic acid was greatly reduced as compared to glutathione. To obtain an in-depth understanding on the degradation of ascorbic acid and glutathione, the activity of enzymes involved in plant antioxidative system via ascorbate-glutathione cycle, as a response towards oxidative stress that took place during storage was determined in this study. The content of total ascorbic acid and glutathione in broccoli florets before and after mechanical processing were found to decrease concurrently with the activity of ascorbic acid peroxidase and glutathione reductase over the experimental storage duration. Meanwhile, the effect of oxidative stress on the content of ascorbic acid and glutathione was apparent during the 6h of incubation after mechanical processing. This phenomenon was demonstrated by the level of oxidative stress biomarkers examined, in which the formation of lipid peroxides, protein carbonyls and DNA oxidised products was positively associated with the degradation of total ascorbic acid and glutathione. Copyright © 2012 Elsevier Ltd. All rights reserved.

Overexpression of CaAPX Induces Orchestrated Reactive Oxygen Scavenging and Enhances Cold and Heat Tolerances in Tobacco

PubMed Central

Wang, Jiangying; Wu, Bin; Fan, Zhengqi; Li, Xinlei; Ni, Sui

2017-01-01

Ascorbate peroxidase (APX) acts indispensably in synthesizing L-ascorbate (AsA) which is pivotal to plant stress tolerance by detoxifying reactive oxygen species (ROS). Enhanced activity of APX has been shown to be a key step for genetic engineering of improving plant tolerance. However it needs a deeper understanding on the maintenance of cellular ROS homeostasis in response to stress. In this study, we identified and characterized an APX (CaAPX) gene from Camellia azalea. Quantitative real-time PCR (qRT-PCR) analysis showed that CaAPX was expressed in all tissues and peaked in immature green fruits; the expression levels were significantly upregulated upon cold and hot stresses. Transgenic plants displayed marked enhancements of tolerance under both cold and heat treatments, and plant growth was correlated with CaAPX expression levels. Furthermore, we monitored the activities of several ROS-scavenging enzymes including Cu/Zn-SOD, CAT, DHAR, and MDHAR, and we showed that stress tolerance was synchronized with elevated activities of ROS-scavenging. Moreover, gene expression analysis of ROS-scavenging enzymes revealed a role of CaAPX to orchestrate ROS signaling in response to temperature stresses. Overall, this study presents a comprehensive characterization of cellular response related to CaAPX expression and provides insights to breed crops with high temperature tolerances. PMID:28386551

Overexpression of CaAPX Induces Orchestrated Reactive Oxygen Scavenging and Enhances Cold and Heat Tolerances in Tobacco.

PubMed

Wang, Jiangying; Wu, Bin; Yin, Hengfu; Fan, Zhengqi; Li, Xinlei; Ni, Sui; He, Libo; Li, Jiyuan

2017-01-01

Ascorbate peroxidase (APX) acts indispensably in synthesizing L-ascorbate (AsA) which is pivotal to plant stress tolerance by detoxifying reactive oxygen species (ROS). Enhanced activity of APX has been shown to be a key step for genetic engineering of improving plant tolerance. However it needs a deeper understanding on the maintenance of cellular ROS homeostasis in response to stress. In this study, we identified and characterized an APX ( CaAPX ) gene from Camellia azalea . Quantitative real-time PCR (qRT-PCR) analysis showed that CaAPX was expressed in all tissues and peaked in immature green fruits; the expression levels were significantly upregulated upon cold and hot stresses. Transgenic plants displayed marked enhancements of tolerance under both cold and heat treatments, and plant growth was correlated with CaAPX expression levels. Furthermore, we monitored the activities of several ROS-scavenging enzymes including Cu/Zn-SOD , CAT , DHAR , and MDHAR , and we showed that stress tolerance was synchronized with elevated activities of ROS-scavenging. Moreover, gene expression analysis of ROS-scavenging enzymes revealed a role of CaAPX to orchestrate ROS signaling in response to temperature stresses. Overall, this study presents a comprehensive characterization of cellular response related to CaAPX expression and provides insights to breed crops with high temperature tolerances.

Interrelationship of dietary lipids and ascorbic acid with hepatic enzymes of cholesterol metabolic pathway.

PubMed

Sen, S; Mukherjee, S

1997-01-01

Effect of unsaturated and saturated fats on cholesterol metabolism was studied in ascorbate sufficient and deficient guineapigs. Experimental animals were made chronic ascorbic acid deficient by allowing oral intake of 0.5 mg ascorbic acid/day/animal. Elevation in serum and liver cholesterol and triglyceride along with depression in cholesterol oxidation and 7 alpha-hydroxylation in liver was observed in unsaturated fat fed guineapigs with ascorbate deficiency. Liver microsomal cytochrome P-450 level was found to be low in ascorbate deficient animals. Polyunsaturated fat intake could not lower the serum cholesterol level in ascorbate deficiency. Today polyunsaturated fat in the diet is encouraged all over the world for its hypocholesterolemic effect. This study indicates that polyunsaturated fat intake with ascorbic acid deficiency may produce hypercholesterolemia.

Changes in structural characteristics of antioxidative soy protein hydrolysates resulting from scavenging of hydroxyl radicals.

PubMed

Zhao, Jing; Xiong, Youling L; McNear, Dave H

2013-02-01

Antioxidant activity of soy protein (SP) and its hydrolyzed peptides has been widely reported. During scavenging of radicals, these antioxidative compounds would be oxidatively modified, but their fate is not understood. The objective of this study was to evaluate the structural characteristics of SP hydrolysates (SPHs), compared to intact SP, when used to neutralize hydroxyl radicals (•OH). SPHs with degree of hydrolysis (DH) 1 to 5 were prepared with Alcalase. Antioxidant activity of SPHs was confirmed by lipid oxidation inhibition measured with thiobarbituric acid-reactive substances, ability to scavenge 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulphonic acid) radicals, and ferrous ion chelation capability. Oxidation of SPHs was initiated by reaction with •OH generated from 0.1 mM FeCl(3) , 20 mM H(2) O(2) , and 1.0 mM ascorbate. After oxidative stress, carbonyl content of SPHs increased by 2- to 3-fold and sulfhydryl groups decreased by up to 42% compared to nonoxidized samples (P < 0.05). Methionine, histidine, and lysine residues were significantly reduced as a result of inactivating •OH (P < 0.05). Attenuated total reflectance-Fourier transform infrared and circular dichroism spectroscopy suggested the conversion of helical structure to strands and turns. Oxidatively modified SPHs had a lower intrinsic fluorescence intensity but similar solubility when compared to nonoxidized samples. These structural changes due to •OH stress may impact the ingredient interaction and functionality of SPHs in food products. © 2013 Institute of Food Technologists®

Simple method for determining human serum 2,2-diphenyl-1-picryl-hydrazyl (DPPH) radical scavenging activity - possible application in clinical studies on dietary antioxidants.

PubMed

Chrzczanowicz, Jacek; Gawron, Anna; Zwolinska, Anna; de Graft-Johnson, Jeffrey; Krajewski, Wojciech; Krol, Maciej; Markowski, Jaroslaw; Kostka, Tomasz; Nowak, Dariusz

2008-01-01

2,2-Diphenyl-1-picryl-hydrazyl (DPPH) radical decomposition in alcohol solution is widely used, characterizing plant antioxidants that can rise in serum after fruit and vegetable intake. However, this test failed reproducible results with serum due to protein precipitation. We describe the application of serum deproteinization with acetonitrile relating to the DPPH test. Assay sensitivity, linearity, repeatability and storage effect were determined in serum samples deproteinized with an equal volume of acetonitrile. Associations between the DPPH test and the ferric reducing ability of serum (FRAP) method, measuring total antioxidant potential, were evaluated in sera from 78 healthy non-smoking men. The effect of a single ingestion of 1 L of cloudy apple juice on the serum DPPH radical scavenging activity in healthy volunteers was also investigated. Assay linearity was within 5-25 microL (r=0.99, p<0.01). With 25 microL-deproteinized serum, coefficient of variation was 4.2% and detection limit was 0.5% of the initial amount of decomposed DPPH radical over 30 min incubation. There was no sera activity decrease over 14 days storage at -20 degrees C. Mean values of DPPH radical scavenging activity and FRAP obtained in human serum were 11.2+/-3.3% and 382.0+/-88.1 micromol/L, respectively. A positive significant linear correlation was observed between these two methods (r=0.42, p<0.01). Serum supplementation with 50 micromol/L of catechin, gallic acid, ascorbic acid or uric acid enhanced DPPH test results. One brisk serving of 1 L of apple juice caused a significant increment of serum DPPH radical scavenging activity (1.9+/-1.9%, p<0.01) in 12 healthy subjects 1 h after juice ingestion. Applicability of the DPPH test to deproteinized serum with acetonitrile revealed numerous advantages, validating its practicability, simplicity and cost effectiveness as a tool in the estimation of antioxidant status in humans.

Antioxidant poly(lactic-co-glycolic) acid nanoparticles made with α-tocopherol-ascorbic acid surfactant.

PubMed

Astete, Carlos E; Dolliver, Debra; Whaley, Meocha; Khachatryan, Lavrent; Sabliov, Cristina M

2011-12-27

The goal of the study was to synthesize a surfactant made of α-tocopherol (vitamin E) and ascorbic acid (vitamin C) of antioxidant properties dubbed as EC, and to use this surfactant to make poly(lactic-co-glycolic) acid (PLGA) nanoparticles. Self-assembled EC nanostructures and PLGA-EC nanoparticles were made by nanoprecipitation, and their physical properties (size, size distribution, morphology) were studied at different salt concentrations, surfactant concentrations, and polymer/surfactant ratios. EC surfactant was shown to form self-assembled nanostructures in water with a size of 22 to 138 nm in the presence of sodium chloride, or 12 to 31 nm when synthesis was carried out in sodium bicarbonate. Polymeric PLGA-EC nanoparticles presented a size of 90 to 126 nm for 40% to 120% mass ratio PLGA to surfactant. For the same mass ratios, the PLGA-Span80 formed particles measured 155 to 216 nm. Span80 formed bilayers, whereas EC formed monolayers at the interfaces. PLGA-EC nanoparticles and EC showed antioxidant activity based on 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging assay measurements using UV and EPR techniques, antioxidant activity which is not characteristic to commercially available Span80. The thiobarbituric acid reactive substances (TBARS) assay for lipid peroxidation showed that PLGA nanoparticles with EC performed better as antioxidants than the EC nanoassembly or the free vitamin C. Nanoparticles were readily internalized by HepG2 cells and were localized in the cytoplasm. The newly synthesized EC surfactant was therefore found successful in forming uniform, small size polymeric nanoparticles of intrinsic antioxidant properties.

Modification of rat detrusor muscle contraction by ascorbic acid and citric acid involving enhanced neurotransmitter release and Ca2+ influx.

PubMed

Dasgupta, Jaydip; Elliott, Ruth A; Tincello, Douglas G

2009-01-01

Consumption of carbonated soft drinks is independently associated with the development of overactive bladder (OR 1.41, 95% Cl 1.02-1.95). We have shown previously that artificial sweeteners, present in carbonated soft drinks, enhanced detrusor muscle contraction. Other constituents of soft drinks are preservatives and antioxidants, we evaluated the effects of two of these, ascorbic acid and citric acid, on the contractile response of isolated rat bladder muscle strips. Detrusor muscle strips were suspended in a perfusion organ bath. We determined the effect of ascorbic acid and citric acid on the contractile responses to electrical field stimulation (EFS) in the absence and presence of atropine, carbachol, alpha, beta methylene ATP, potassium and calcium. Ascorbic acid and citric acid (10(-7) M to 10(-3) M) enhanced the contractile response to 10 Hz EFS compared to control (P < 0.01). The frequency and amplitude of spontaneous bladder contractions were enhanced in the presence of ascorbic acid and citric acid by 14%, 21%, 21%, and 11% respectively. Ascorbic acid 10(-4) M significantly increased the atropine resistant response to EFS 5 Hz by 37% (P < 0.01) and inhibited contraction in response to carbachol 10(-4) M by 24%, (P < 0.05). Both ascorbic acid 10(-4) M and citric acid 10(-5) M significantly enhanced maximum contractile responses to alpha, beta methylene ATP, KCI and calcium compared to control. Ascorbic acid and citric acid augmented bladder muscle contraction possibly by enhanced Ca(2+) influx. Presynaptic neurotransmitter release was enhanced by ascorbic acid. Carbonated beverages containing preservatives may aggravate symptoms of OAB. (c) 2009 Wiley-Liss, Inc.

Free Radical Scavenging Properties of Skin and Pulp Extracts of Different Grape Cultivars In Vitro and Attenuation of H2O2-Induced Oxidative Stress in Liver Tissue Ex Vivo.

PubMed

Singha, Indrani; Das, Subir Kumar

2015-07-01

Grapes are the richest source of antioxidants due to the presence of potent bioactive phytochemicals. In this study, the phytochemical contents, scavenging activities and protective role against H2O2-induced oxidative stress in liver tissue ex vivo of four grape (Vitis vinifera) cultivars extracts, namely Flame seedless (black), Kishmish chorni (black with reddish brown), Red globe (red) and Thompson seedless mutant (green), were evaluated. The total phenolics and flavonoids content in pulp or skin fractions of different grape cultivars were in the range of 47.6-310 mg gallic acid equivalent/g fresh weight (fw), and 46.6-733.3 µg catechin equivalent/g fw respectively. The scavenging activities in skin of different grape varieties against 2,2-diphenyl-1-picrylhydrazyl (44-58 %), hydrogen peroxide (15.3-18.6 %), and hydroxyl radicals (50-85 %), were higher than pulp of the corresponding cultivars. These scavenging activities of grape extracts were found to be significantly (p < 0.01) correlated with the levels of total phenols, flavonoids and ascorbic acid. Liver tissues from goat treated with H2O2 (500 μM) showed significantly decreased GSH content by 42.9 % and activities of catalase by 50 % and glutathione reductase by 66.6 %; while increased thiobarbituric acid reactive substances and nitric oxide level by 2.53- and 0.86-fold, respectively, and activity of glutathione S-transferase by 0.96-fold. Grape skin extracts showed the stronger protective activity against H2O2-induced oxidative stress in liver tissue ex vivo, than its pulp of any cultivar; and the Flame seedless (black) cultivar showed the highest potential. In conclusion, our study suggested that the higher antioxidant potential, phytochemical contents and significant scavenging capacities in pulp and skin of grape extracts showed the protective action of grape extracts against H2O2-induced oxidative stress in liver tissue ex vivo.

Beta-glycerophosphate accelerates RANKL-induced osteoclast formation in the presence of ascorbic acid.

PubMed

Noh, A Long Sae Mi; Yim, Mijung

2011-03-01

Despite numerous reports of the synergistic effects of beta-glycerophosphate and ascorbic acid in inducing the differentiation of osteoblasts, little is known about their roles in osteoclastic differentiation. Therefore, we investigated the effect of beta-glycerophosphate on osteoclastogenesis in the presence of ascorbic acid using primary mouse bone marrow cultures treated with macrophage colony-stimulating factor (M-CSF) and receptor activator of nuclear factor (NF)-kappaB ligand (RANKL). Beta-Glycerophosphate dose-dependently increased RANKL-induced osteoclast formation in the presence of ascorbic acid. This stimulatory effect was apparent when beta-glycerophosphate and ascorbic acid were only added during the late stages of the culture period, indicating that they influence later events in osteoclastic differentiation. While the combination of beta-glycerophosphate and ascorbic acid inhibited RANKL-stimulated activation of ERK and p38, and degradation of IkappaB, it increased the induction of c-Fos and NFATc1. In addition, beta-glycerophosphate and ascorbic acid together enhanced the induction of COX-2 following RANKL stimulation. Taken together, our data suggest that beta-glycerophosphate and ascorbic acid have synergistic effects on osteoclast formation, increasing RANKL-mediated induction of c-Fos, NFATc1 and COX-2 in osteoclast precursors.

Peroxydisulfate Oxidation of L-Ascorbic Acid for Its Direct Spectrophotometric Determination in Dietary Supplements

NASA Astrophysics Data System (ADS)

Salkić, M.; Selimović, A.; Pašalić, H.; Keran, H.

2014-03-01

A selective and accurate direct spectrophotometric method was developed for the determination of L-as cor bic acid in dietary supplements. Background correction was based on the oxidation of L-ascorbic acid by potassi um peroxydisulfate in an acidic medium. The molar absorptivity of the proposed method was 1.41 · 104 l/(mol · cm) at 265 nm. The method response was linear up to an L-ascorbic acid concentration of 12.00 μg/ml. The detection limit was 0.11 μg/ml, and the relative standard deviation was 0.9 % (n = 7) for 8.00 μg/ml L-ascorbic acid. Other compounds commonly found in the dietary supplements did not interfere with the detection of L-ascorbic acid. The proposed procedure was successfully applied to the determination of L-ascorbic acid in these supplements, and the results obtained agreed with those obtained by iodine titration.

[Antioxidative activities of two metabolites of cultured marine fungus, Halorosellinia oceanicum 323 in vitro].

PubMed

Luo, Jinghui; Yang, Yingbao; Lin, Yongcheng; Chen, Zhiliang; Jiang, Guangce

2004-03-01

To investigate the antioxidative effects of 323-A and 323-B, two isomers extracted from the metabolites of cultured marine fungus, Halorosellinia oceanicum 323 in vitro. NADH-PMS-NBT system was used to produce superoxide free radical (O2*-), EDTANa2-Fe(II)-H2O2 system to generate hydroxyl free radical (*OH), H2O2 to stimulate oxidative hemolysis of erythrocytes of rats, Cys-Fe2+ to induce malondialdehyde (MDA) production in homogenates, and ferrous-ascorbic acid system to increase the turbidity of mitochondria suspension in the liver of rats. And the antioxidative activities of 323-A and 323-B were studied. 323-A and 323-B not only scavenge O2*- and *OH produced by the experimental systems directly, but also inhibit H2O2 stimulated oxidative hemolysis of erythrocytes of rats, depress MDA production in homogenates induced by Cys-Fe2+ system, and reduce the turbidity of mitochondria suspension in the liver of rats increased by ferrous-ascorbic acid system in vitro. 323-A and 323-B showed comprehensive cleaning actions on free radicals and protective effects on the functions of tissues and cells against oxidative lesion. The results suggested that the marine microorganic metabolites might be a novel and profound source of antioxidative reagents.

Degradation kinetic modelling of ascorbic acid and colour intensity in pasteurised blood orange juice during storage.

PubMed

Remini, Hocine; Mertz, Christian; Belbahi, Amine; Achir, Nawel; Dornier, Manuel; Madani, Khodir

2015-04-15

The stability of ascorbic acid and colour intensity in pasteurised blood orange juice (Citrus sinensis [L.] Osbeck) during one month of storage was investigated at 4-37 °C. The effects of ascorbic acid fortification (at 100, 200 mg L(-1)) and deaeration, temperature/time storage on the kinetic behaviour were determined. Ascorbic acid was monitored by HPLC-DAD and colour intensity by spectrophotometric measurements. Degradation kinetics were best fitted by first-order reaction models for both ascorbic acid and colour intensity. Three models (Arrhenius, Eyring and Ball) were used to assess the temperature-dependent degradation. Following the Arrhenius model, activation energies were ranged from 51 to 135 kJ mol(-1) for ascorbic acid and from 49 to 99 kJ mol(-1) for colour intensity. The effect of storage temperature and deaeration are the most influent factors on kinetics degradation, while the fortification revealed no significant effect on ascorbic acid content and colour intensity. Copyright © 2014 Elsevier Ltd. All rights reserved.

A failure in energy metabolism and antioxidant uptake precede symptoms of Huntington's disease in mice.

PubMed

Acuña, Aníbal I; Esparza, Magdalena; Kramm, Carlos; Beltrán, Felipe A; Parra, Alejandra V; Cepeda, Carlos; Toro, Carlos A; Vidal, René L; Hetz, Claudio; Concha, Ilona I; Brauchi, Sebastián; Levine, Michael S; Castro, Maite A

2013-01-01

Huntington's disease has been associated with a failure in energy metabolism and oxidative damage. Ascorbic acid is a powerful antioxidant highly concentrated in the brain where it acts as a messenger, modulating neuronal metabolism. Using an electrophysiological approach in R6/2 HD slices, we observe an abnormal ascorbic acid flux from astrocytes to neurons, which is responsible for alterations in neuronal metabolic substrate preferences. Here using striatal neurons derived from knock-in mice expressing mutant huntingtin (STHdhQ cells), we study ascorbic acid transport. When extracellular ascorbic acid concentration increases, as occurs during synaptic activity, ascorbic acid transporter 2 (SVCT2) translocates to the plasma membrane, ensuring optimal ascorbic acid uptake for neurons. In contrast, SVCT2 from cells that mimic HD symptoms (dubbed HD cells) fails to reach the plasma membrane under the same conditions. We reason that an early impairment of ascorbic acid uptake in HD neurons could lead to early metabolic failure promoting neuronal death.

A failure in energy metabolism and antioxidant uptake precede symptoms of Huntington’s disease in mice

PubMed Central

Acuña, Aníbal I.; Esparza, Magdalena; Kramm, Carlos; Beltrán, Felipe A.; Parra, Alejandra V.; Cepeda, Carlos; Toro, Carlos A.; Vidal, René L.; Hetz, Claudio; Concha, Ilona I.; Brauchi, Sebastián; Levine, Michael S.; Castro, Maite A.

2013-01-01

Huntington’s disease has been associated with a failure in energy metabolism and oxidative damage. Ascorbic acid is a powerful antioxidant highly concentrated in the brain where it acts as a messenger, modulating neuronal metabolism. Using an electrophysiological approach in R6/2 HD slices, we observe an abnormal ascorbic acid flux from astrocytes to neurons, which is responsible for alterations in neuronal metabolic substrate preferences. Here using striatal neurons derived from knock-in mice expressing mutant huntingtin (STHdhQ cells), we study ascorbic acid transport. When extracellular ascorbic acid concentration increases, as occurs during synaptic activity, ascorbic acid transporter 2 (SVCT2) translocates to the plasma membrane, ensuring optimal ascorbic acid uptake for neurons. In contrast, SVCT2 from cells that mimic HD symptoms (dubbed HD cells) fails to reach the plasma membrane under the same conditions. We reason that an early impairment of ascorbic acid uptake in HD neurons could lead to early metabolic failure promoting neuronal death. PMID:24336051

A failure in energy metabolism and antioxidant uptake precede symptoms of Huntington’s disease in mice

NASA Astrophysics Data System (ADS)

Acuña, Aníbal I.; Esparza, Magdalena; Kramm, Carlos; Beltrán, Felipe A.; Parra, Alejandra V.; Cepeda, Carlos; Toro, Carlos A.; Vidal, René L.; Hetz, Claudio; Concha, Ilona I.; Brauchi, Sebastián; Levine, Michael S.; Castro, Maite A.

2013-12-01

Huntington’s disease has been associated with a failure in energy metabolism and oxidative damage. Ascorbic acid is a powerful antioxidant highly concentrated in the brain where it acts as a messenger, modulating neuronal metabolism. Using an electrophysiological approach in R6/2 HD slices, we observe an abnormal ascorbic acid flux from astrocytes to neurons, which is responsible for alterations in neuronal metabolic substrate preferences. Here using striatal neurons derived from knock-in mice expressing mutant huntingtin (STHdhQ cells), we study ascorbic acid transport. When extracellular ascorbic acid concentration increases, as occurs during synaptic activity, ascorbic acid transporter 2 (SVCT2) translocates to the plasma membrane, ensuring optimal ascorbic acid uptake for neurons. In contrast, SVCT2 from cells that mimic HD symptoms (dubbed HD cells) fails to reach the plasma membrane under the same conditions. We reason that an early impairment of ascorbic acid uptake in HD neurons could lead to early metabolic failure promoting neuronal death.

A highly sensitive kinetic spectrophotometric method for the determination of ascorbic Acid in pharmaceutical samples.

PubMed

Shishehbore, Masoud Reza; Aghamiri, Zahra

2014-01-01

In this study, a new reaction system for quantitative determination of ascorbic acid was introduced. The developed method is based on inhibitory effect of ascorbic acid on the Orange G-bromate system. The change in absorbance was followed spectrophotometrically at 478 nm. The dependence of sensitivity on the reaction variables including reagents concentration, temperature and time was investigated. Under optimum experimental conditions, calibration curve was linear over the range 0.7 - 33.5 μg mL(-1) of ascorbic acid including two linear segments and the relative standard deviations (n = 6) for 5.0 and 20.0 μg mL(-1) of ascorbic acid were 1.08 and 1.02%, respectively. The limit of detection was 0.21 μg mL(-) (1) of ascorbic acid. The effect of diverse species was also investigated. The developed method was successfully applied for the determination of ascorbic acid in pharmaceutical samples. The results were in a good agreement with those of reference method.

Ascorbic acid, catalase and chlorpromazine reduce cryopreservation-induced damages to crossbred bull spermatozoa.

PubMed

Paudel, K P; Kumar, S; Meur, S K; Kumaresan, A

2010-04-01

The present study evaluated the effectiveness of ascorbic acid, catalase, chlorpromazine and their combinations in reducing the cryodamages to crossbred bull (Bos taurus x Bos indicus) spermatozoa. A total of 32 ejaculates (eight each from four bulls) were diluted in Tris-citric acid-fructose-egg yolk-glycerol extender. Each ejaculate was split into six parts (five treatment and one control). Treatment groups included 10 mm ascorbic acid, 0.1 mm chlorpromazine, 200 IU/ml catalase, 10 mm ascorbic acid + 0.1 mm chlorpromazine or 200 IU/ml catalase + 0.1 mm chlorpromazine in the extender. Fluorescent probes (Fluorescein isothiocyanate--Pisum sativum agglutinin + Propidium iodide) were used for the assessment of spermatozoa viability and acrosomal status. The proportion of acrosome intact live (AIL), acrosome intact dead, acrosome reacted live and acrosome reacted dead sperm was assessed in fresh, equilibrated and frozen-thawed semen. The functional status of the sperm was assessed using hypo-osmotic sperm swelling test (HOSST). Activities of acrosin and hyaluronidase enzyme were also determined. Lipid peroxidation level was assayed based on the melonaldehyde (MDA) production. In cryopreserved semen, the values of AIL spermatozoa, HOSST response, hyaluronidase and acrosin activity were reduced by 53%, 47%, 34% and 54%, respectively from their initial values in fresh semen. However, MDA level was threefold higher in the frozen-thawed sperm compared with fresh sperm. Significant (p < 0.05) improvement in motility, viability, HOSST response, retention of hyaluonidase and acrosin and reduction in MDA was recorded in ascorbic acid, catalase, ascorbic acid + chlorpromazine and catalase + chlorpromazine incorporated groups. The percentage of AIL sperm was significantly (p < 0.05) higher in ascorbic acid, catalase and ascorbic acid + chlorpromazine incorporated groups compared with the control. Chlorpromazine alone did not improve the post-thaw semen quality but when combined with either ascorbic acid or catalase, improvement in semen quality was noticed. It was inferred that incorporation of ascorbic acid, catalase and ascorbic acid + chlorpromazine in semen extender improved the post-thaw semen quality in crossbred bulls.

The kinetics of oxidation of bilirubin and ascorbic acid in solution

NASA Astrophysics Data System (ADS)

Solomonov, A. V.; Rumyantsev, E. V.; Kochergin, B. A.; Antina, E. V.

2012-07-01

The results of a comparative study of the oxidation of bilirubin, ascorbic acid, and their mixture in aqueous solutions under the action of air oxygen and hydrogen peroxide are presented. The observed and true rate constants for the oxidation reactions were determined. It was shown that the oxidation of tetrapyrrole pigment occurred under these conditions bypassing the stage of biliverdin formation to monopyrrole products. Simultaneous oxidation of bilirubin and ascorbic acid was shown to be accompanied by the inhibition of ascorbic acid oxidation by bilirubin, whereas ascorbic acid itself activated the oxidation of bilirubin.

A metabolic switch in brain: glucose and lactate metabolism modulation by ascorbic acid.

PubMed

Castro, Maite A; Beltrán, Felipe A; Brauchi, Sebastián; Concha, Ilona I

2009-07-01

In this review, we discuss a novel function of ascorbic acid in brain energetics. It has been proposed that during glutamatergic synaptic activity neurons preferably consume lactate released from glia. The key to this energetic coupling is the metabolic activation that occurs in astrocytes by glutamate and an increase in extracellular [K(+)]. Neurons are cells well equipped to consume glucose because they express glucose transporters and glycolytic and tricarboxylic acid cycle enzymes. Moreover, neuronal cells express monocarboxylate transporters and lactate dehydrogenase isoenzyme 1, which is inhibited by pyruvate. As glycolysis produces an increase in pyruvate concentration and a decrease in NAD(+)/NADH, lactate and glucose consumption are not viable at the same time. In this context, we discuss ascorbic acid participation as a metabolic switch modulating neuronal metabolism between rest and activation periods. Ascorbic acid is highly concentrated in CNS. Glutamate stimulates ascorbic acid release from astrocytes. Ascorbic acid entry into neurons and within the cell can inhibit glucose consumption and stimulate lactate transport. For this switch to occur, an ascorbic acid flow is necessary between astrocytes and neurons, which is driven by neural activity and is part of vitamin C recycling. Here, we review the role of glucose and lactate as metabolic substrates and the modulation of neuronal metabolism by ascorbic acid.

A cobalt oxyhydroxide-modified upconversion nanosystem for sensitive fluorescence sensing of ascorbic acid in human plasma

NASA Astrophysics Data System (ADS)

Cen, Yao; Tang, Jun; Kong, Xiang-Juan; Wu, Shuang; Yuan, Jing; Yu, Ru-Qin; Chu, Xia

2015-08-01

Ascorbic acid (AA), a potent antioxidant readily scavenging reactive species, is a crucial micronutrient involved in many biochemical processes. Here, we have developed a cobalt oxyhydroxide (CoOOH)-modified upconversion nanosystem for fluorescence sensing of AA activity in human plasma. The nanosystem consists of upconversion nanoparticles (UCNPs) NaYF4:30% Yb,0.5% Tm@NaYF4, which serve as energy donors, and CoOOH nanoflakes formed on the surface of UCNPs, which act as efficient energy acceptors. The fluorescence resonance energy transfer (FRET) process from the UCNPs to the absorbance of the CoOOH nanoflakes occurs in the nanosystem. The AA-mediated specific redox reaction reduces CoOOH into Co2+, leading to the inhibition of FRET, and resulting in the recovery of upconversion emission spectra. On the basis of these features, the nanosystem can be used for sensing AA activity with sensitivity and selectivity. Moreover, due to the minimizing background interference provided by UCNPs, the nanosystem has been applied to monitoring AA levels in human plasma sample with satisfactory results. The proposed approach may potentially provide an analytical platform for research and clinical diagnosis of AA related diseases.Ascorbic acid (AA), a potent antioxidant readily scavenging reactive species, is a crucial micronutrient involved in many biochemical processes. Here, we have developed a cobalt oxyhydroxide (CoOOH)-modified upconversion nanosystem for fluorescence sensing of AA activity in human plasma. The nanosystem consists of upconversion nanoparticles (UCNPs) NaYF4:30% Yb,0.5% Tm@NaYF4, which serve as energy donors, and CoOOH nanoflakes formed on the surface of UCNPs, which act as efficient energy acceptors. The fluorescence resonance energy transfer (FRET) process from the UCNPs to the absorbance of the CoOOH nanoflakes occurs in the nanosystem. The AA-mediated specific redox reaction reduces CoOOH into Co2+, leading to the inhibition of FRET, and resulting in the recovery of upconversion emission spectra. On the basis of these features, the nanosystem can be used for sensing AA activity with sensitivity and selectivity. Moreover, due to the minimizing background interference provided by UCNPs, the nanosystem has been applied to monitoring AA levels in human plasma sample with satisfactory results. The proposed approach may potentially provide an analytical platform for research and clinical diagnosis of AA related diseases. Electronic supplementary information (ESI) available. See DOI: 10.1039/c5nr03588k

Quantification of Mesophyll Resistance and Apoplastic Ascorbic Acid as an Antioxidant for Tropospheric Ozone in Durum Wheat (Triticum durum Desf. cv. Camacho)

PubMed Central

de la Torre, Daniel

2008-01-01

The daily variations in cellular and apoplastic ascorbic acid and dehydroascorbic acid levels in a Mediterranean durum wheat cultivar (Triticum durum Desf. cv. Camacho) were analyzed in order to relate them to ambient ozone exposure and to subsequent stomatally absorbed ozone fluxes. The aim of this study is to prove the effectiveness and accuracy of a computer model (SODA) to calculate the mesophyll resistance (rm) to ozone uptake, the percentage of ozone detoxification by apoplastic ascorbic acid, and the ozone flux to the plasmalemma (Fm) in a Mediterranean durum wheat cultivar. These calculated factors were related to apoplastic ascorbic acid levels and to ambient ozone concentrations. These relationships were obtained with a view to explaining the detoxification of ozone by apoplastic ascorbic acid. Ozone detoxifications of up to 52% were found at midday, when maximum ozone concentrations and maximum apoplastic ascorbic acid are seen. Mesophyll resistance was minimum at this time, and ozone flux to the plasmalemma was reduced because of the reaction of ozone with apoplastic ascorbic acid. PMID:19082416

Quantification of mesophyll resistance and apoplastic ascorbic acid as an antioxidant for tropospheric ozone in durum wheat (Triticum durum Desf. cv. Camacho).

PubMed

de la Torre, Daniel

2008-12-14

The daily variations in cellular and apoplastic ascorbic acid and dehydroascorbic acid levels in a Mediterranean durum wheat cultivar (Triticum durum Desf. cv. Camacho) were analyzed in order to relate them to ambient ozone exposure and to subsequent stomatally absorbed ozone fluxes. The aim of this study is to prove the effectiveness and accuracy of a computer model (SODA) to calculate the mesophyll resistance (rm) to ozone uptake, the percentage of ozone detoxification by apoplastic ascorbic acid, and the ozone flux to the plasmalemma (Fm) in a Mediterranean durum wheat cultivar. These calculated factors were related to apoplastic ascorbic acid levels and to ambient ozone concentrations. These relationships were obtained with a view to explaining the detoxification of ozone by apoplastic ascorbic acid. Ozone detoxifications of up to 52% were found at midday, when maximum ozone concentrations and maximum apoplastic ascorbic acid are seen. Mesophyll resistance was minimum at this time, and ozone flux to the plasmalemma was reduced because of the reaction of ozone with apoplastic ascorbic acid.

Ascorbic Acid as a Standard for Iodometric Titrations. An Analytical Experiment for General Chemistry

NASA Astrophysics Data System (ADS)

Silva, Cesar R.; Simoni, Jose A.; Collins, Carol H.; Volpe, Pedro L. O.

1999-10-01

Ascorbic acid is suggested as the weighable compound for the standardization of iodine solutions in an analytical experiment in general chemistry. The experiment involves an iodometric titration in which iodine reacts with ascorbic acid, oxidizing it to dehydroascorbic acid. The redox titration endpoint is determined by the first iodine excess that is complexed with starch, giving a deep blue-violet color. The results of the titration of iodine solution using ascorbic acid as a calibration standard were compared with the results acquired by the classic method using a standardized solution of sodium thiosulfate. The standardization of the iodine solution using ascorbic acid was accurate and precise, with the advantages of saving time and avoiding mistakes due to solution preparation. The colorless ascorbic acid solution gives a very clear and sharp titration end point with starch. It was shown by thermogravimetric analysis that ascorbic acid can be dried at 393 K for 2 h without decomposition. This experiment allows general chemistry students to perform an iodometric titration during a single laboratory period, determining with precision the content of vitamin C in pharmaceutical formulations.

Degradation of L-Ascorbic Acid in the Amorphous Solid State.

PubMed

Sanchez, Juan O; Ismail, Yahya; Christina, Belinda; Mauer, Lisa J

2018-03-01

Ascorbic acid degradation in amorphous solid dispersions was compared to its degradation in the crystalline state. Physical blends and lyophiles of ascorbic acid and polymers (pectins and polyvinylpyrrolidone [PVP]) were prepared initially at 50:50 (w/w), with further studies using the polymer that best inhibited ascorbic acid crystallization in the lyophiles in 14 vitamin : PVP ratios. Samples were stored in controlled environments (25 to 60 °C, 0% to 23% RH) for 1 mo and analyzed periodically to track the physical appearance, change in moisture content, physical state (powder x-ray diffraction and polarized light microscopy), and vitamin loss (high performance liquid chromatography) over time. The glass transition temperatures of select samples were determined using differential scanning calorimetry, and moisture sorption profiles were generated. Ascorbic acid in the amorphous form, even in the glassy amorphous state, was more labile than in the crystalline form in some formulations at the highest storage temperature. Lyophiles stored at 25 and 40 °C and those in which ascorbic acid had crystallized at 60 °C (≥70% ascorbic acid : PVP) had no significant difference in vitamin loss (P > 0.05) relative to physical blend controls, and the length of storage had little effect. At 60 °C, amorphous ascorbic acid lyophiles (≤60% ascorbic acid : PVP) lost significantly more vitamin (P < 0.05) relative to physical blend controls after 1 wk, and vitamin loss significantly increased over time. In these lyophiles, vitamin degradation also significantly increased (P < 0.05) at lower proportions of ascorbic acid, a scenario likely encountered in foods wherein vitamins are naturally present or added at low concentrations and production practices may promote amorphization of the vitamin. Vitamin C is one of the most unstable vitamins in foods. This study documents that amorphous ascorbic acid is less stable than crystalline ascorbic acid in some environments (for example, higher temperatures within 1 wk), especially when the vitamin is present at low concentrations in a product. These findings increase the understanding of how material science properties influence the stability of vitamin C. © 2018 Institute of Food Technologists®.

Protective and Therapeutic Agents for War Gases - Solutions of BAL

DTIC Science & Technology

1945-04-02

Ascorbic Acid 1.07 Thiosorbitol :7 7§ Catechol 1.07 Menthol p-Toluene Sulfinic Gum Tragacanth .76 Acid 1.07 Glycine .74 Formamidlne Sulfinic...Hydrazine hydrochlorlde d-iao-ascorbic acid Iflcotlnlc acid Ascorbic acid "Avonex" (oat flour concentrate) Sulfanilamide Camphor Menthol Thiodiglycol

Ascorbate as a Biosynthetic Precursor in Plants

PubMed Central

Debolt, Seth; Melino, Vanessa; Ford, Christopher M.

2007-01-01

Background and Aims l-Ascorbate (vitamin C) has well-documented roles in many aspects of redox control and anti-oxidant activity in plant cells. This Botanical Briefing highlights recent developments in another aspect of l-ascorbate metabolism: its function as a precursor for specific processes in the biosynthesis of organic acids. Scope The Briefing provides a summary of recent advances in our understanding of l-ascorbate metabolism, covering biosynthesis, translocation and functional aspects. The role of l-ascorbate as a biosynthetic precursor in the formation of oxalic acid, l-threonic acid and l-tartaric acid is described, and progress in elaborating the mechanisms of the formation of these acids is reviewed. The potential conflict between the two roles of l-ascorbate in plant cells, functional and biosynthetic, is highlighted. Conclusions Recent advances in the understanding of l-ascorbate catabolism and the formation of oxalic and l-tartaric acids provide compelling evidence for a major role of l-ascorbate in plant metabolism. Combined experimental approaches, using classic biochemical and emerging ‘omics’ technologies, have provided recent insight to previously under-investigated areas. PMID:17098753

Metabolic Conversion of l-Ascorbic Acid to Oxalic Acid in Oxalate-accumulating Plants 1

PubMed Central

Yang, Joan C.; Loewus, Frank A.

1975-01-01

l-Ascorbic acid-1-14C and its oxidation product, dehydro-l-ascorbic acid, produced labeled oxalic acid in oxalate-accumulating plants such as spinach seedlings (Spinacia oleracea) and the detached leaves of woodsorrel (Oxalis stricta and O. oregana), shamrock (Oxalis adenopylla), and begonia (Begonia evansiana). In O. oregana, conversion occurred equally well in the presence or absence of light. This relationship between l-ascorbic acid metabolism and oxalic acid formation must be given careful consideration in attempts to explain oxalic accumulation in plants. PMID:16659288

Dried extracts of Encholirium spectabile (Bromeliaceae) present antioxidant and photoprotective activities in vitro

PubMed Central

de Oliveira, Raimundo Gonçalves; Souza, Grasielly Rocha; Guimarães, Amanda Leite; de Oliveira, Ana Paula; Silva Morais, Amanda Caroline; da Cruz Araújo, Edigênia Cavalcante; Nunes, Xirley Pereira; Almeida, Jackson Roberto Guedes da Silva

2013-01-01

The antioxidant and photoprotective activities of dried extracts from the leaves of Encholirium spectabile were investigated. It was also evaluated the total phenolic and flavonoid contents by the Folin–Ciocalteu and aluminum chloride methods, respectively. Antioxidant activities of the extracts were evaluated by using of 2,2-diphenyl-1-picrylhydrazil (DPPH) radical scavenging and β-carotene–linoleic acid bleaching and compared with ascorbic acid, butylated hydroxyanisole (BHA) and butylated hydroxytoluene (BHT) used as reference compounds. The photoprotective effect was evaluated by the spectrophotometric method. The most significant total phenolic and flavonoid contents was of 188.50 ± 27.50 mg of gallic acid equivalent/g and 129.70 ± 4.59 mg of catechin equivalent/g, respectively, for chloroform fraction (Es-CHCl3). The Es-CHCl3 also presented the best antioxidant activity (IC50 25.35 ± 4.35 μg/ml) for DPPH scavenging. The ethanol extract (Es-EtOH), Es-CHCl3 and the fraction ethyl acetate (Es-AcOEt) showed characteristic absorption bands in regions UVB and UVA in a concentration-dependent manner. Es-CHCl3 presented the highest sun protection factor SPF (8.89 ± 2.11). It shows the possibility to use this extract as sunscreen in pharmaceutical preparations. PMID:24396251

Sequential injection redox or acid-base titration for determination of ascorbic acid or acetic acid.

PubMed

Lenghor, Narong; Jakmunee, Jaroon; Vilen, Michael; Sara, Rolf; Christian, Gary D; Grudpan, Kate

2002-12-06

Two sequential injection titration systems with spectrophotometric detection have been developed. The first system for determination of ascorbic acid was based on redox reaction between ascorbic acid and permanganate in an acidic medium and lead to a decrease in color intensity of permanganate, monitored at 525 nm. A linear dependence of peak area obtained with ascorbic acid concentration up to 1200 mg l(-1) was achieved. The relative standard deviation for 11 replicate determinations of 400 mg l(-1) ascorbic acid was 2.9%. The second system, for acetic acid determination, was based on acid-base titration of acetic acid with sodium hydroxide using phenolphthalein as an indicator. The decrease in color intensity of the indicator was proportional to the acid content. A linear calibration graph in the range of 2-8% w v(-1) of acetic acid with a relative standard deviation of 4.8% (5.0% w v(-1) acetic acid, n=11) was obtained. Sample throughputs of 60 h(-1) were achieved for both systems. The systems were successfully applied for the assays of ascorbic acid in vitamin C tablets and acetic acid content in vinegars, respectively.

Expression of Ascorbic Acid Oxidase in Zucchini Squash (Cucurbita pepo L.).

PubMed

Lin, L S; Varner, J E

1991-05-01

The expression of ascorbic acid oxidase was studied in zucchini squash (Cucurbita pepo L.), one of the most abundant natural sources of the enzyme. In the developing fruit, specific activity of ascorbic acid oxidase was highest between 4 and 6 days after anthesis. Protein and mRNA levels followed the same trend as enzyme activity. Highest growth rate of the fruit occurred before 6 days after anthesis. Within a given fruit, ascorbic acid oxidase activity and mRNA level were highest in the epidermis, and lowest in the central placental region. In leaf tissue, ascorbic acid oxidase activity was higher in young leaves, and very low in old leaves. Within a given leaf, enzyme activity was highest in the fast-growing region (approximately the lower third of the blade), and lowest in the slow-growing region (near leaf apex). High expression of ascorbic acid oxidase at a stage when rapid growth is occurring (in both fruits and leaves), and localization of the enzyme in the fruit epidermis, where cells are under greatest tension during rapid growth in girth, suggest that ascorbic acid oxidase might be involved in reorganization of the cell wall to allow for expansion. Based on the known chemistry of dehydroascorbic acid, the end product of the ascorbic acid oxidase-catalyzed reaction, we have proposed several hypotheses to explain how dehydroascorbic acid might cause cell wall "loosening."

Salivary ascorbic acid levels in betel quid chewers: A biochemical study.

PubMed

Shetty, Shishir R; Babu, Subhas; Kumari, Suchetha; Prasad, Rajendra; Bhat, Supriya; Fazil, K A

2013-07-01

Quid chewing practice has been a part of our tradition since centuries with little known evidence of oral cancer. However, recent trends show a rise in occurrence of oral cancer often associated with tobacco and arecanut usage. Ascorbic acid is an important salivary antioxidant. Betel leaf which is used in quid is known to contain ascorbic acid. The aim of our study was to assess the salivary levels of ascorbic acid in traditional quid chewers so as to determine whether the betel leaf has protective antioxidant action. Salivary ascorbic acid levels of 60 subjects were estimated using the Dinitrophenyl hydrazine method. The results revealed that quid chewers who used betel leaf had higher salivary ascorbic acid content compared to nonbetel leaf quid chewers. This could possibly be due to the protective antioxidants in the betel leaf.

PLASMID DNA DAMAGE CAUSED BY METHYLATED ARSENICALS, ASCORBIC ACID AND HUMAN LIVER FERRITIN

EPA Science Inventory

PLASMID DNA DAMAGE CAOUSED BY METHYLATED ARSENICALS, ASCORBIC ACID AND HUMAN LIVER FERRITIN

ABSTRACT

Both dimethylarsinic acid (DMA(V)) and dimethylarsinous acid (DMA(III)) release iron from human liver ferritin (HLF) with or without the presence of ascorbic acid. ...

Effects of ascorbic acid and antioxidants on color, lipid oxidation and volatiles of irradiated ground beef

NASA Astrophysics Data System (ADS)

Ahn, D. U.; Nam, K. C.

2004-09-01

Beef loins with 3 different aging times after slaughter were ground, added with none, 0.1% ascorbic acid, 0.01% sesamol+0.01% α-tocopherol, or 0.1% ascorbic acid+0.01% sesamol+0.01% tocopherol. The meats were packaged in oxygen-permeable bags, irradiated at 2.5 kGy, and color, oxidation-reduction potential (ORP), lipid oxidation and volatile profiles were determined. Irradiation decreased the redness of ground beef, and visible color of beef changed from a bright red to a green/brown depending on the age of meat. Addition of ascorbic acid prevented color changes in irradiated beef, and the effect of ascorbic acid became greater as the age of meat or storage time after irradiation increased. The ground beef added with ascorbic acid had lower ORP than control, and the low ORP of meat helped maintaining the heme pigments in reduced form. During aerobic storage, S-volatiles disappeared while volatile aldehydes significantly increased in irradiated beef. Addition of ascorbic acid at 0.1% or sesamol+α-tocopherol at each 0.01% level to ground beef prior to irradiation were effective in reducing lipid oxidation and S-volatiles. As storage time increased, however, the antioxidant effect of sesamol+tocopherol in irradiated ground beef was superior to that of ascorbic acid.

Effects of L-ascorbic acid on physicochemical characteristics of wheat starch.

PubMed

Majzoobi, Mahsa; Radi, Mohsen; Farahnaky, Asgar; Tongdang, Tawee

2012-03-01

The main objective of this study was to determine the effects of l-ascorbic acid, as a permitted additive in bakery products, on characteristics of wheat starch. Suspensions of wheat starch (30%, w/w) in water containing 140 mg/kg ascorbic acid before and after gelatinization were prepared and studied using different techniques. The results of scanning electron microscopy showed that some spots appeared on the surface of the starch granules as a result of the addition of ascorbic acid. However, no changes in the starch crystalline pattern and its degree of crystallinity were observed by X-ray diffraction technique. For ungelatinized samples, no difference in the pasting properties of the samples was determined by the rapid visco analyzer, whereas for the gelatinized samples, peak and final viscosities decreased for the samples contained ascorbic acid. Determination of the intrinsic viscosities of the samples showed that addition of ascorbic acid to the gelatinized samples reduced the intrinsic viscosity. In general, it was found that ascorbic acid had some degradation effects on wheat starch molecules particularly after gelatinization. © 2012 Institute of Food Technologists®

A direct ascorbate fuel cell with an anion exchange membrane

NASA Astrophysics Data System (ADS)

Muneeb, Omar; Do, Emily; Tran, Timothy; Boyd, Desiree; Huynh, Michelle; Ghosn, Gregory; Haan, John L.

2017-05-01

Ascorbic Acid (Vitamin C) is investigated as a renewable alternative fuel for alkaline direct liquid fuel cells (DLFCs). The environmentally- and biologically-friendly compound, L-ascorbic acid (AA) has been modeled and studied experimentally under acidic fuel cell conditions. In this work, we demonstrate that ascorbic acid is a more efficient fuel in alkaline media than in acidic media. An operating direct ascorbate fuel cell is constructed with the combination of L-ascorbic acid and KOH as the anode fuel, air or oxygen as the oxidant, a polymer anion exchange membrane, metal or carbon black anode materials and metal cathode catalyst. Operation of the fuel cell at 60 °C using 1 M AA and 1 M KOH as the anode fuel and electrolyte, respectively, and oxygen gas at the cathode, produces a maximum power density of 73 mW cm-2, maximum current density of 497 mA cm-2 and an open circuit voltage of 0.90 V. This performance is significantly greater than that of an ascorbic acid fuel cell with a cation exchange membrane, and it is competitive with alkaline DLFCs fueled by alcohols.

Ascorbic acid deficiency decreases hepatic cytochrome P-450, especially CYP2B1/2B2, and simultaneously induces heme oxygenase-1 gene expression in scurvy-prone ODS rats.

PubMed

Kobayashi, Misato; Hoshinaga, Yukiko; Miura, Natsuko; Tokuda, Yuki; Shigeoka, Shigeru; Murai, Atsushi; Horio, Fumihiko

2014-01-01

The mechanisms underlying the decrease in hepatic cytochrome P-450 (CYP) content in ascorbic acid deficiency was investigated in scurvy-prone ODS rats. First, male ODS rats were fed a diet containing sufficient ascorbic acid (control) or a diet without ascorbic acid (deficient) for 18 days, with or without the intraperitoneal injection of phenobarbital. Ascorbic acid deficiency decreased hepatic microsomal total CYP content, CYP2B1/2B2 protein, and mitochondrial cytochrome oxidase (COX) complex IV subunit I protein, and simultaneously increased heme oxygenase-1 protein in microsomes and mitochondria. Next, heme oxygenase-1 inducers, that is lipopolysaccharide and hemin, were administered to phenobaribital-treated ODS rats fed sufficient ascorbic acid. The administration of these inducers decreased hepatic microsomal total CYP content, CYP2B1/2B2 protein, and mitochondrial COX complex IV subunit I protein. These results suggested that the stimulation of hepatic heme oxygenase-1 expression by ascorbic acid deficiency caused the decrease in CYP content in liver.

Combined effect of selenium and ascorbic acid on alcohol induced hyperlipidemia in male guinea pigs.

PubMed

Asha, G S; Indira, M

2004-02-01

Alcoholics usually suffer from malnutrition and are especially deficient in micronutrients like vitamin C, selenium and Zn. In the present study, combined effects of selenium and ascorbic acid on alcohol-induced hyperlipidemia were studied in guinea pigs. Four groups of male guinea pigs were maintained for 45 days as follows: control (1 mg ascorbate (AA)/100 g body mass/day), ethanol (900 mg ethanol/100 g body mass + 1 mg AA/100 g body mass/day), selenium+ascorbic acid [(25 mg AA + 0.05 mg Se)/100 g body mass/day], ethanol+selenium+ascorbic acid [(25 mg AA + 0.05 mg Se + 900 mg ethanol)/100 g body mass/day]. Co-administration of selenium and ascorbic acid along with alcohol reduced the concentration of all lipids, as also evidenced from the decreased activities of hydroxymethylglutaryl-CoA reductase and enhanced activities of plasma lecithin cholesterol acyl transferase and lipoprotein lipase. Concentrations of bile acids were increased. We conclude that the supplementation of Se and ascorbic acid reduced alcohol induced hyperlipidemia, by decreased synthesis and increased catabolism.

Ascorbic acid supplementation partially prevents the delayed reproductive development in juvenile male rats exposed to rosuvastatin since prepuberty.

PubMed

Leite, Gabriel Adan Araújo; Figueiredo, Thamiris Moreira; Sanabria, Marciana; Dias, Ana Flávia Mota Gonçalves; Silva, Patrícia Villela E; Martins Junior, Airton da Cunha; Barbosa Junior, Fernando; Kempinas, Wilma De Grava

2017-10-01

Dyslipidemias are occurring earlier in the population due to the increase of obesity and bad eating habits. Rosuvastatin inhibits the enzyme HMG-CoA reductase, decreasing total cholesterol. Ascorbic acid is an important antioxidant compound for male reproductive system. This study aimed to evaluate whether ascorbic acid supplementation may prevent the reproductive damage provoked by rosuvastatin administration at prepuberty. Male pups were distributed into six experimental groups that received saline solution 0.9%, 3 or 10mg/kg/day of rosuvastatin, 150mg/day of ascorbic acid, or 150mg/day of ascorbic acid associated with 3 or 10mg/kg/day of rosuvastatin from post-natal day (PND) 23 until PND53. Rosuvastatin-treated groups showed delayed puberty installation, androgen depletion and impairment on testicular and epididymal morphology. Ascorbic acid partially prevented these reproductive damages. In conclusion, rosuvastatin exposure is a probable risk to reproductive development and ascorbic acid supplementation may be useful to prevent the reproductive impairment of rosuvastatin exposure. Copyright © 2017 Elsevier Inc. All rights reserved.

Low brain ascorbic acid increases susceptibility to seizures in mouse models of decreased brain ascorbic acid transport and Alzheimer's disease.

PubMed

Warner, Timothy A; Kang, Jing-Qiong; Kennard, John A; Harrison, Fiona E

2015-02-01

Seizures are a known co-occurring symptom of Alzheimer's disease, and they can accelerate cognitive and neuropathological dysfunction. Sub-optimal vitamin C (ascorbic acid) deficiency, that is low levels that do not lead the sufferer to present with clinical signs of scurvy (e.g. lethargy, hemorrhage, hyperkeratosis), are easily obtainable with insufficient dietary intake, and may contribute to the oxidative stress environment of both Alzheimer's disease and epilepsy. The purpose of this study was to test whether mice that have diminished brain ascorbic acid in addition to carrying human Alzheimer's disease mutations in the amyloid precursor protein (APP) and presenilin 1 (PSEN1) genes, had altered electrical activity in the brain (electroencephalography; EEG), and were more susceptible to pharmacologically induced seizures. Brain ascorbic acid was decreased in APP/PSEN1 mice by crossing them with sodium vitamin C transporter 2 (SVCT2) heterozygous knockout mice. These mice have an approximately 30% decrease in brain ascorbic acid due to lower levels of SVCT2 that supplies the brain with ASC. SVCT2+/-APP/PSEN1 mice had decreased ascorbic acid and increased oxidative stress in brain, increased mortality, faster seizure onset latency following treatment with kainic acid (10 mg/kg i.p.), and more ictal events following pentylenetetrazol (50 mg/kg i.p.) treatment. Furthermore, we report the entirely novel phenomenon that ascorbic acid deficiency alone increased the severity of kainic acid- and pentylenetetrazol-induced seizures. These data suggest that avoiding ascorbic acid deficiency may be particularly important in populations at increased risk for epilepsy and seizures, such as Alzheimer's disease. Copyright © 2014 Elsevier B.V. All rights reserved.

Salivary ascorbic acid levels in betel quid chewers: A biochemical study

PubMed Central

Shetty, Shishir R.; Babu, Subhas; Kumari, Suchetha; Prasad, Rajendra; Bhat, Supriya; Fazil, K. A.

2013-01-01

Background: Quid chewing practice has been a part of our tradition since centuries with little known evidence of oral cancer. However, recent trends show a rise in occurrence of oral cancer often associated with tobacco and arecanut usage. Ascorbic acid is an important salivary antioxidant. Betel leaf which is used in quid is known to contain ascorbic acid. Aim: The aim of our study was to assess the salivary levels of ascorbic acid in traditional quid chewers so as to determine whether the betel leaf has protective antioxidant action. Materials and Methods: Salivary ascorbic acid levels of 60 subjects were estimated using the Dinitrophenyl hydrazine method. Results: The results revealed that quid chewers who used betel leaf had higher salivary ascorbic acid content compared to nonbetel leaf quid chewers. This could possibly be due to the protective antioxidants in the betel leaf. PMID:24455594

D-erythroascorbic acid: Its preparations, chemistry, and metabolism (fungi and plants)

DOE Office of Scientific and Technical Information (OSTI.GOV)

Loewus, F.A.; Seib, P.A.

1991-01-01

The origin of oxalate in plants has received considerable attention and glycolate metabolism has been generally regarded as a prime precursor candidate although studies on the metabolism of L-ascorbic acid single out that plant constituent as well. Experiments with oxalate-accumulating plants that contain little or no tartaric acid revealed the presence of a comparable L-ascorbic acid metabolism with the exception that the cleavage products were oxalic acid and L-threonic acid or products of L-threonic acid metabolism. A reasonable mechanism for cleavage of L-ascorbic acid at the endiolic bond is found in studies on the photooxygenation of L-ascorbic acid. Presumably, analogsmore » of L-ascorbic acid that differ only in the substituent at C4 also form a hydroperoxide in the presence of alkaline hydrogen peroxide and subsequently yield oxalic acid and the corresponding aldonic acid or its lactone. We became interested in such a possibility when we discovered that L-ascorbic acid was rare or absent in certain yeasts and fungi whereas a L-ascorbic acid analog, D-glycero-pent-2-enono- 1,4-lactone (D-erythroascorbic acid), was present. It has long been known that oxalate occurs in yeasts and fungi and its production plays a role in plant pathogenesis. As to the biosynthetic origin of fungal oxalic acid there is little information although it is generally assumed that oxaloacetate or possibly, glycolate, might be that precursor.« less

D-erythroascorbic acid: Its preparations, chemistry, and metabolism (fungi and plants). Final report

DOE Office of Scientific and Technical Information (OSTI.GOV)

Loewus, F.A.; Seib, P.A.

1991-12-31

The origin of oxalate in plants has received considerable attention and glycolate metabolism has been generally regarded as a prime precursor candidate although studies on the metabolism of L-ascorbic acid single out that plant constituent as well. Experiments with oxalate-accumulating plants that contain little or no tartaric acid revealed the presence of a comparable L-ascorbic acid metabolism with the exception that the cleavage products were oxalic acid and L-threonic acid or products of L-threonic acid metabolism. A reasonable mechanism for cleavage of L-ascorbic acid at the endiolic bond is found in studies on the photooxygenation of L-ascorbic acid. Presumably, analogsmore » of L-ascorbic acid that differ only in the substituent at C4 also form a hydroperoxide in the presence of alkaline hydrogen peroxide and subsequently yield oxalic acid and the corresponding aldonic acid or its lactone. We became interested in such a possibility when we discovered that L-ascorbic acid was rare or absent in certain yeasts and fungi whereas a L-ascorbic acid analog, D-glycero-pent-2-enono- 1,4-lactone (D-erythroascorbic acid), was present. It has long been known that oxalate occurs in yeasts and fungi and its production plays a role in plant pathogenesis. As to the biosynthetic origin of fungal oxalic acid there is little information although it is generally assumed that oxaloacetate or possibly, glycolate, might be that precursor.« less

Ascorbic acid and tannins from Emblica officinalis Gaertn. Fruits--a revisit.

PubMed

Majeed, Muhammed; Bhat, Beena; Jadhav, Atul N; Srivastava, Jyotish S; Nagabhushanam, Kalyanam

2009-01-14

The fruits of Emblica officinalis Gaertn. (Euphorbiaceae), also known as amla in Ayurveda, are considered to be a rich source of ascorbic acid. However, the antioxidant activities exhibited by E. officinalis extract are superior to those of ascorbic acid itself. Low molecular hydrolyzable tannins emblicanins A and B have been suggested in the earlier literature to be the contributory antioxidant molecules in the extract. This work finds no evidence for the presence of emblicanins A and B in the extract. In addition, the high content of ascorbic acid is also questionable due to previous nonidentification of coeluting mucic acid gallates. This paper reports a new HPLC method to detect even trace amounts of ascorbic acid in E. officinalis fruit juice or extract.

Effects of Pre-Converted Nitrite from Red Beet and Ascorbic Acid on Quality Characteristics in Meat Emulsions

PubMed Central

Kim, Hyun-Wook; Hwang, Ko-Eun

2017-01-01

We investigated the effects of fermented red beet extract and ascorbic acid on color development in meat emulsions. The pH of meat emulsions containing red beet extract decreased with an increase in the amount of extract added. The redness of the treated meat emulsions was higher than that of the control with no added nitrite or fermented red beet extract (p<0.05), though the redness of the meat emulsions treated with fermented red beet extract only was lower than in that treated with both fermented red beet extract and ascorbic acid (p<0.05). The highest VBN, TBARS, and total viable count values were observed in the control, and these values in the meat emulsions treated with fermented red beet extract were higher than in that treated with both fermented red beet extract and ascorbic acid (p<0.05). E. coli and coliform bacteria were not found in any of the meat emulsions tested. Treatment T2, containing nitrite and ascorbic acid, had the highest overall acceptability score (p<0.05); however, there was no significant difference between the T2 treatment and the T6 treatment, which contained 10% pre-converted nitrite from red beet extract and 0.05% ascorbic acid (p>0.05). The residual nitrite content of the meat emulsions treated with ascorbic acid was lower than in those treated without ascorbic acid (p<0.05). Thus, the combination of fermented red beet extract and ascorbic acid could be a viable alternative to synthetic nitrite for the stability of color development in meat emulsions. PMID:28515652

Effect of different levels of an ascorbic acid and tea mixture on nonheme iron absorption from a typical Tunisian meal fed to healthy rats.

PubMed

Hamdauoui, M; Doghri, T; Tritar, B

1995-01-01

The aim of our study was to evaluate the bioavailability of iron from a typical Tunisian meal 'couscous' provided to healthy rats with or without appropriate mixtures of tea plus ascorbic acid and to search for the optimal amount of ascorbic acid able to overcome the inhibitory effect of tea prepared under realistic Tunisian circumstances. Our findings show that a tea decoction (100 mg/ml) reduced nonheme iron absorption from couscous by 50% (16.5 vs. 33.1%; p < 0.01). In contrast, administration of 20 mg ascorbic acid increased nonheme iron absorption from couscous by more than 100% (66.8 vs. 33.1%; p < 0.001). Administration of ascorbic acid (20 mg) in a tea decoction (100 mg/ml) completely counteracted the inhibiting effect of tea and significantly improved the nonheme iron absorption from couscous (34 vs. 33% in the control group; NS). The same effect was shown when 10 mg ascorbic acid was added to the tea decoction; however, 5 mg ascorbic acid was not able to overcome the inhibitory effect of tea on nonheme iron absorption from couscous (33.1 vs. 19.4%; p < 0.01). Our findings demonstrate that a molar ratio of ascorbic acid and tea equal or superior to 0.25 or 0.50 is necessary to overcome the inhibitory effect in rats of tea prepared under Tunisian circumstances. In relation to human nutrition, for Tunisians who regularly drink tea, we suggest a much greater amount of ascorbic acid than that normally recommended for normal subjects.

Effects of Pre-Converted Nitrite from Red Beet and Ascorbic Acid on Quality Characteristics in Meat Emulsions.

PubMed

Choi, Yun-Sang; Kim, Tae-Kyung; Jeon, Ki-Hong; Park, Jong-Dae; Kim, Hyun-Wook; Hwang, Ko-Eun; Kim, Young-Boong

2017-01-01

We investigated the effects of fermented red beet extract and ascorbic acid on color development in meat emulsions. The pH of meat emulsions containing red beet extract decreased with an increase in the amount of extract added. The redness of the treated meat emulsions was higher than that of the control with no added nitrite or fermented red beet extract ( p <0.05), though the redness of the meat emulsions treated with fermented red beet extract only was lower than in that treated with both fermented red beet extract and ascorbic acid ( p <0.05). The highest VBN, TBARS, and total viable count values were observed in the control, and these values in the meat emulsions treated with fermented red beet extract were higher than in that treated with both fermented red beet extract and ascorbic acid ( p <0.05). E. coli and coliform bacteria were not found in any of the meat emulsions tested. Treatment T2, containing nitrite and ascorbic acid, had the highest overall acceptability score ( p <0.05); however, there was no significant difference between the T2 treatment and the T6 treatment, which contained 10% pre-converted nitrite from red beet extract and 0.05% ascorbic acid ( p >0.05). The residual nitrite content of the meat emulsions treated with ascorbic acid was lower than in those treated without ascorbic acid ( p <0.05). Thus, the combination of fermented red beet extract and ascorbic acid could be a viable alternative to synthetic nitrite for the stability of color development in meat emulsions.

Antioxidant and antiproliferative activities of methanolic extract from a neglected agricultural product: corn cobs.

PubMed

Melo-Silveira, Raniere Fagundes; Fidelis, Gabriel Pereira; Viana, Rony Lucas Silva; Soeiro, Vinícius Campelo; Silva, Rodrigo Augusto da; Machado, Daisy; Costa, Leandro Silva; Ferreira, Carmen Veríssima; Oliveira Rocha, Hugo Alexandre

2014-04-24

Neglected agricultural products (NAPs) are defined as discarded material in agricultural production. Corn cobs are a major waste of agriculture maize. Here, a methanolic extract from corn cobs (MEC) was obtained. MEC contains phenolic compounds, protein, carbohydrates (1.4:0.001:0.001). We evaluated the in vitro and in vivo antioxidant potential of MEC. Furthermore, its antiproliferative property against tumor cells was assessed through MTT assays and proteins related to apoptosis in tumor cells were examined by western blot. MEC showed no hydroxyl radical scavenger capacity, but it showed antioxidant activity in Total Antioxidant Capacity and DPPH scavenger ability assays. MEC showed higher Reducing Power than ascorbic acid and exhibited high Superoxide Scavenging activity. In tumor cell culture, MEC increased catalase, metallothionein and superoxide dismutase expression in accordance with the antioxidant tests. In vivo antioxidant test, MEC restored SOD and CAT, decreased malondialdehyde activities and showed high Trolox Equivalent Antioxidant Capacity in animals treated with CCl4. Furthermore, MEC decreased HeLa cells viability by apoptosis due an increase of Bax/Bcl-2 ratio, caspase 3 active. Protein kinase C expression increased was also detected in treated tumor cells. Thus, our findings pointed out the biotechnological potential of corn cobs as a source of molecules with pharmacological activity.

In vitro evaluation of antimicrobial and antioxidant activities of methanolic extract of Jasminum humile leaves.

PubMed

Nain, Parminder; Kumar, Ashok; Sharma, Sunil; Nain, Jaspreet

2011-10-01

To evaluate in vitro antimicrobial and antioxidant activities of methanolic extract of Jasminum humile (J. humile) leaves extract. Methanolic extract of J. humile was evaluated for its antimicrobial activity by using agar well diffusion method & their possible antioxidant assay by two complementary test systems, namely DPPH and hydrogen peroxide scavenging activity. These various antioxidant activities were compared to standard antioxidants such as ascorbic acid for both the tests. In the DPPH & hydrogen peroxide scavenging activity, the IC(50) value of methanol extract was 70.43 μg/mL & 60.79 μg/mL respectively. Further, the extract showed inhibitory activity for Gram-positive and negative bacteria at different concentrations. The maximum antibacterial activity of extract was exhibited against Staphylococcus aureus (S. aureus) at concentration 50 mg/mL when compared with ciprofloxacin These results clearly indicate that J. humile is effective in scavenging free radicals and has the potential to be a powerful antioxidant. Thus, the results obtained in the present study indicate that J. humile leaves extract could be considered as a potential source of natural antioxidants and that could be used as an effective source against bacterial diseases. Copyright © 2011 Hainan Medical College. Published by Elsevier B.V. All rights reserved.

Flavonoids as Putative Inducers of the Transcription Factors Nrf2, FoxO, and PPARγ

PubMed Central

Duckstein, Nils; Hasler, Mario; Rimbach, Gerald

2017-01-01

Dietary flavonoids have been shown to extend the lifespan of some model organisms and may delay the onset of chronic ageing-related diseases. Mechanistically, the effects could be explained by the compounds scavenging free radicals or modulating signalling pathways. Transcription factors Nrf2, FoxO, and PPARγ possibly affect ageing by regulating stress response, adipogenesis, and insulin sensitivity. Using Hek-293 cells transfected with luciferase reporter constructs, we tested the potency of flavonoids from different subclasses (flavonols, flavones, flavanols, and isoflavones) to activate these transcription factors. Under cell-free conditions (ABTS and FRAP assays), we tested their free radical scavenging activities and used α-tocopherol and ascorbic acid as positive controls. Most of the tested flavonoids, but not the antioxidant vitamins, stimulated Nrf2-, FoxO-, and PPARγ-dependent promoter activities. Flavonoids activating Nrf2 also tended to induce a FoxO and PPARγ response. Interestingly, activation patterns of cellular stress response by flavonoids were not mirrored by their activities in ABTS and FRAP assays, which depended mostly on hydroxylation in the flavonoid B ring and, in some cases, extended that of the vitamins. In conclusion, the free radical scavenging properties of flavonoids do not predict whether these molecules can stimulate a cellular response linked to activation of longevity-associated transcription factors. PMID:28761622

Industrial production of L-ascorbic Acid (vitamin C) and D-isoascorbic acid.

PubMed

Pappenberger, Günter; Hohmann, Hans-Peter

2014-01-01

L-ascorbic acid (vitamin C) was first isolated in 1928 and subsequently identified as the long-sought antiscorbutic factor. Industrially produced L-ascorbic acid is widely used in the feed, food, and pharmaceutical sector as nutritional supplement and preservative, making use of its antioxidative properties. Until recently, the Reichstein-Grüssner process, designed in 1933, was the main industrial route. Here, D-sorbitol is converted to L-ascorbic acid via 2-keto-L-gulonic acid (2KGA) as key intermediate, using a bio-oxidation with Gluconobacter oxydans and several chemical steps. Today, industrial production processes use additional bio-oxidation steps with Ketogulonicigenium vulgare as biocatalyst to convert D-sorbitol to the intermediate 2KGA without chemical steps. The enzymes involved are characterized by a broad substrate range, but remarkable regiospecificity. This puzzling specificity pattern can be understood from the preferences of these enyzmes for certain of the many isomeric structures which the carbohydrate substrates adopt in aqueous solution. Recently, novel enzymes were identified that generate L-ascorbic acid directly via oxidation of L-sorbosone, an intermediate of the bio-oxidation of D-sorbitol to 2KGA. This opens the possibility for a direct route from D-sorbitol to L-ascorbic acid, obviating the need for chemical rearrangement of 2KGA. Similar concepts for industrial processes apply for the production of D-isoascorbic acid, the C5 epimer of L-ascorbic acid. D-isoascorbic acid has the same conformation at C5 as D-glucose and can be derived more directly than L-ascorbic acid from this common carbohydrate feed stock.

Selenylation Modification of Degraded Polysaccharide from Enteromorpha prolifera and Its Biological Activities

NASA Astrophysics Data System (ADS)

Lv, Haitao; Duan, Ke; Shan, Hu

2018-04-01

Polysaccharide extracted from Enteromorpha prolifera possessed excellent biological activities, but its molecular weight was greatly high which influenced the activity. Organic Se had higher biological activities and was safer than inorganic Se species. In the present study, Enteromorpha polysaccharide was degraded to low molecular weight by free-radical degradation method of H2O2 and ascorbic acid. By single factor and orthogonal experiments, the optimal degradation conditions were reaction time of 2 h, reaction temperature of 50°C, H2O2/ascorbic acid (n/n=1:1) concentration of 15 mmol L-1, and solid-liquid ratio of 1:50 (g mL-1). Then, the degraded polysaccharide was chemically modified to obtain its selenide derivatives by nitric acid-sodium selenite method. The selenium content was 1137.29 μg g-1, while the content of sulfate radical had no change. IR spectra indicated that the selenite ester group was formed. Degraded polysaccharide selenide was characterized and evaluated for antioxidant, antifungal and antibacterial activities. The results showed that degraded polysaccharide selenide had strong capacity of scavenging DPPH and ·OH free radical. It had significant antibacterial properties for Escherichia coli, Bacillus subtilis and Salmonella spp., and it also had significant antifungal properties for Apple anthrax. The result ascertained degradation and selenylation modification did not change the main structure of polysaccharides. It was possible that free-radical degradation was an effective way for enhancing antioxidant activity to decrease molecular weight of polysaccharides.

Morinda citrifolia L. fruit extracts modulates H2O2-induced oxidative stress in human liposarcoma SW872 cells.

PubMed

Ruhomally, Z; Somanah, J; Bahorun, T; Neergheen-Bhujun, V S

2016-07-01

Morinda citrifolia L. commonly known as noni is used by the pharmaceutical and cosmetic industries due to the plethora of pharmacological activities of its metabolites. In Mauritius, the fruits of M. citrifolia are used in folk medicine against a number of indications. The present study aimed at evaluating the antioxidant activity of ripe and unripe noni fruit at both biochemical and cellular levels. Using an array of established assay systems, the fruit antioxidant propensity was assessed in terms of its radical scavenging, iron reducing and metal chelating potentials. Ascorbic acid, total phenolic and total flavonoid contents of the fruits were also determined. The ascorbic acid content of ripe noni was 76.24 ± 1.13 mg/100 g while total phenolics of ripe and unripe fruit extracts were 748.40 ± 8.85 μg and 770.34 ± 2.27 μg GAE g(-1) FW respectively. Both the ripe and unripe extracts of M. citrifolia were potent scavengers of nitric oxide, superoxide and hydroxyl radicals. The ferric reducing capacity ranged from 11.26 ± 0.33 to 11.90 ± 0.20 mM Fe(2+) g(-1) FW while the IC50 values for the iron (II) chelating power were 0.50 ± 0.01 and 1.74 ± 0.01 g FW/mL for the ripe and unripe fruit extracts respectively. Cellular studies additionally demonstrated that noni were able to dose-dependently counteract accumulation of reactive oxygen species (ROS)-induced oxidative stress, a potential obesogenic factor within human liposarcoma SW872 cells as well as significantly restore cell death within the concentration range of 0.106-0.813 g/mL. Results reported herein suggest noni as an interesting source of prophylactic antioxidants modulated by its polyphenol composition.

21 CFR 182.3013 - Ascorbic acid.

Code of Federal Regulations, 2011 CFR

2011-04-01

... 21 Food and Drugs 3 2011-04-01 2011-04-01 false Ascorbic acid. 182.3013 Section 182.3013 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) FOOD FOR HUMAN... acid. (a) Product. Ascorbic acid. (b) Conditions of use. This substance is generally recognized as safe...

Optimization of Alkaline Extraction and Bioactivities of Polysaccharides from Rhizome of Polygonatum odoratum

PubMed Central

Chen, Yong; Yin, Luoyi; Zhang, Xuejiao; Wang, Yan; Chen, Qiuzhi; Jin, Chenzhong; Wang, Jihua

2014-01-01

The present study is to explore the optimal extraction parameters, antioxidant activity, and antimicrobial activity of alkaline soluble polysaccharides from rhizome of Polygonatum odoratum. The optimal extraction parameters were determined as the following: NaOH concentration (A) 0.3 M, temperature (B) 80°C, ratio of NaOH to solid (C) 10-fold, and extraction time (D) 4 h, in which ratio of NaOH to solid was a key factor. The order of the factors was ratio of NaOH to solid (fold, C) > extraction temperature (°C, B) > NaOH concentration (M, A) > extraction time (h, D). The monosaccharide compositions of polysaccharides from P. odoratum were rhamnose, mannose, xylose, and arabinose with the molecular ratio of 31.78, 31.89, 11.11, and 1.00, respectively. The reducing power, the 1, 1-diphenyl-2-picryl-hydrazil (DPPH) radical scavenging rate, the hydroxyl radicals scavenging rate, and the inhibition rate to polyunsaturated fatty acid (PUFA) peroxidation of the alkaline soluble polysaccharides from P. odoratum at 1 mg/mL were 9.81%, 52.84%, 19.22%, and 19.42% of ascorbic acid at the same concentration, respectively. They also showed antimicrobial activity against pathogenic bacteria Staphylococcus aureus, Pseudomonas aeruginosa, Bacillus subtilis, and Escherichia coli. PMID:25093173

Aqueous humour and ultraviolet radiation.

PubMed

Ringvold, A

1980-01-01

Studies on the ultraviolet ray absorption in the aqueous humour of rabbit, cat, monkey, guinea pig, and rat showed marked species differences. In the rabbit aqueous the ascorbic acid, the proteins, and some amino acids (tyrosine, phenylalanine, cystine, and tryptophane) are together responsible for the total absorption, and a very great part of it refers to the ascorbic acid content. Accordingly, species with significant amounts of ascorbic acid in the aqueous (monkey, rabbit, guinea pig) have a greater absorption capacity towards ultraviolet radiation than species (cat, rat) lacking this substance. This effect of the ascorbic acid may contribute in protecting the lens against the most biotoxic ultraviolet rays. It seems that the ascorbic acid concentration is highest in the aqueous of typical day animals and lowest in species being active in the dark, indicating a correlation between the aqueous' ascorbic acid level and the quantity of incident light on the eye. The possible significance of changed aqueous ultraviolet ray absorption in the pathogenesis of human cataract development is discussed.

Sodium-dependent Vitamin C transporter 2 deficiency impairs myelination and remyelination after injury: Roles of collagen and demethylation.

PubMed

Röhr, Dominik; Halfter, Hartmut; Schulz, Jörg B; Young, Peter; Gess, Burkhard

2017-07-01

Peripheral nerve myelination involves rapid production of tightly bound lipid layers requiring cholesterol biosynthesis and myelin protein expression, but also a collagen-containing extracellular matrix providing mechanical stability. In previous studies, we showed a function of ascorbic acid in peripheral nerve myelination and extracellular matrix formation in adult mice. Here, we sought the mechanism of action of ascorbic acid in peripheral nerve myelination using different paradigms of myelination in vivo and in vitro. We found impaired myelination and reduced collagen expression in Sodium-dependent Vitamin C Transporter 2 heterozygous mice (SVCT2 +/- ) during peripheral nerve development and after peripheral nerve injury. In dorsal root ganglion (DRG) explant cultures, hypo-myelination could be rescued by precoating with different collagen types. The activity of the ascorbic acid-dependent demethylating Ten-eleven-translocation (Tet) enzymes was reduced in ascorbic acid deprived and SVCT2 +/- DRG cultures. Further, in ascorbic acid-deprived DRG cultures, methylation of a CpG island in the collagen alpha1 (IV) and alpha2 (IV) bidirectional promoter region was increased compared to wild-type and ascorbic acid treated controls. Taken together, these results provide further evidence for the function of ascorbic acid in myelination and extracellular matrix formation in peripheral nerves and suggest a putative molecular mechanism of ascorbic acid function in Tet-dependent demethylation of collagen promoters. © 2017 Wiley Periodicals, Inc.

Ameliorative Effect of Chronic Supplementation of Protocatechuic Acid Alone and in Combination with Ascorbic Acid in Aniline Hydrochloride Induced Spleen Toxicity in Rats.

PubMed

Khairnar, Upasana; Upaganlawar, Aman; Upasani, Chandrashekhar

2016-01-01

Background. Present study was designed to evaluate the protective effects of protocatechuic acid alone and in combination with ascorbic acid in aniline hydrochloride induced spleen toxicity in rats. Materials and Methods. Male Wistar rats of either sex (200-250 g) were used and divided into different groups. Spleen toxicity was induced by aniline hydrochloride (100 ppm) in drinking water for a period of 28 days. Treatment group received protocatechuic acid (40 mg/kg/day, p.o.), ascorbic acid (40 mg/kg/day, p.o.), and combination of protocatechuic acid (20 mg/kg/day, p.o.) and ascorbic acid (20 mg/kg/day, p.o.) followed by aniline hydrochloride. At the end of treatment period serum and tissue parameters were evaluated. Result. Rats supplemented with aniline hydrochloride showed a significant alteration in body weight, spleen weight, feed consumption, water intake, hematological parameters (haemoglobin content, red blood cells, white blood cells, and total iron content), tissue parameters (lipid peroxidation, reduced glutathione, and nitric oxide content), and membrane bound phosphatase (ATPase) compared to control group. Histopathology of aniline hydrochloride induced spleen showed significant damage compared to control rats. Treatment with protocatechuic acid along with ascorbic acid showed better protection as compared to protocatechuic acid or ascorbic acid alone in aniline hydrochloride induced spleen toxicity. Conclusion. Treatment with protocatechuic acid and ascorbic acid in combination showed significant protection in aniline hydrochloride induced splenic toxicity in rats.

Dietary ascorbic acid and subsequent change in body weight and waist circumference: associations may depend on genetic predisposition to obesity - a prospective study of three independent cohorts

PubMed Central

2014-01-01

Background Cross-sectional data suggests that a low level of plasma ascorbic acid positively associates with both Body Mass Index (BMI) and Waist Circumference (WC). This leads to questions about a possible relationship between dietary intake of ascorbic acid and subsequent changes in anthropometry, and whether such associations may depend on genetic predisposition to obesity. Hence, we examined whether dietary ascorbic acid, possibly in interaction with the genetic predisposition to a high BMI, WC or waist-hip ratio adjusted for BMI (WHR), associates with subsequent annual changes in weight (∆BW) and waist circumference (∆WC). Methods A total of 7,569 participants’ from MONICA, the Diet Cancer and Health study and the INTER99 study were included in the study. We combined 50 obesity associated single nucleotide polymorphisms (SNPs) in four genetic scores: a score of all SNPs and a score for each of the traits (BMI, WC and WHR) with which the SNPs associate. Linear regression was used to examine the association between ascorbic acid intake and ΔBW or ΔWC. SNP-score × ascorbic acid interactions were examined by adding product terms to the models. Results We found no significant associations between dietary ascorbic acid and ∆BW or ∆WC. Regarding SNP-score × ascorbic acid interactions, each additional risk allele of the 14 WHR associated SNPs associated with a ∆WC of 0.039 cm/year (P = 0.02, 95% CI: 0.005 to 0.073) per 100 mg/day higher ascorbic acid intake. However, the association to ∆WC only remained borderline significant after adjustment for ∆BW. Conclusion In general, our study does not support an association between dietary ascorbic acid and ∆BW or ∆WC, but a diet with a high content of ascorbic acid may be weakly associated to higher WC gain among people who are genetically predisposed to a high WHR. However, given the quite limited association any public health relevance is questionable. PMID:24886192

Involvement of polyamine oxidase in abscisic acid-induced cytosolic antioxidant defense in leaves of maize.

PubMed

Xue, Beibei; Zhang, Aying; Jiang, Mingyi

2009-03-01

Using pharmacological and biochemical approaches, the role of maize polyamine oxidase (MPAO) in abscisic acid (ABA)-induced antioxidant defense in leaves of maize (Zea mays L.) plants was investigated. Exogenous ABA treatment enhanced the expression of the MPAO gene and the activities of apoplastic MPAO. Pretreatment with two different inhibitors for apoplastic MPAO partly reduced hydrogen peroxide (H2O2) accumulation induced by ABA and blocked the ABA-induced expression of the antioxidant genes superoxide dismutase 4 and cytosolic ascorbate peroxidase and the activities of the cytosolic antioxidant enzymes. Treatment with spermidine, the optimum substrate of MPAO, also induced the expression and the activities of the antioxidant enzymes, and the upregulation of the antioxidant enzymes was prevented by two inhibitors of MPAO and two scavengers of H2O2. These results suggest that MPAO contributes to ABA-induced cytosolic antioxidant defense through H2O2, a Spd catabolic product.

Studies on cytotoxic and clot lysis activity of probiotically fermented cocktail juice prepared using Camellia sinensis and Punica grantum

NASA Astrophysics Data System (ADS)

Biswas, Ananya; Deori, Meenakshi; Nivetha, A.; Mohansrinivasan, V.

2017-11-01

In the current research the effect of probiotic microorganisms viz; Lactococcus lactis and Lactobacillus plantarum on fermentation of Camellia sinensis and Punica grantum was studied. In vitro test were done to analyze the anticancer, antioxidant and atherosclerosis (clot lysis) properties of fermented juice. The juice was fermented for 48 and 96h, during which concentration of phenolic content, total acid content and free radical scavenging activity of the sample was analyzed by DPPH assay (α, α-diphenyl-β-picrylhydrazyl). Dropping of pH was observed after 48 h of fermentation. The clot lysis activity was found to be 80 % in 100μl concentration of fermented cocktail juice. The 96 h fermented sample has shown around 70% inhibition against colon cancer cell lines. Analytical study of HPLC proves the organic acid production such as ascorbic acid in superior amount for 96h of fermented sample, Based on the retention time, the corresponding peaks were detected at 4.919 and 4.831 min.

Ascorbic Acid Determination in Commercial Fruit Juice Samples by Cyclic Voltammetry

PubMed Central

Pisoschi, Aurelia Magdalena; Danet, Andrei Florin; Kalinowski, Slawomir

2008-01-01

A method was developed for assessing ascorbic acid concentration in commercial fruit juice by cyclic voltammetry. The anodic oxidation peak for ascorbic acid occurs at about 490 mV on a Pt disc working electrode (versus SCE). The influence of the potential sweep speed on the peak height was studied. The obtained calibration graph shows a linear dependence between peak height and ascorbic acid concentration in the domain (0.1–10 mmol·L−1). The equation of the calibration graph was y = 6.391x + 0.1903 (where y represents the value of intensity measured for the anodic peak height, expressed as μA and x the analyte concentration, as mmol·L−1, r2 = 0.9995, r.s.d. = 1.14%, n = 10, Cascorbic acid = 2 mmol·L−1). The developed method was applied to ascorbic acid assessment in fruit juice. The ascorbic acid content determined ranged from 0.83 to 1.67 mmol·L−1 for orange juice, from 0.58 to 1.93 mmol·L−1 for lemon juice, and from 0.46 to 1.84 mmol·L−1 for grapefruit juice. Different ascorbic acid concentrations (from standard solutions) were added to the analysed samples, the degree of recovery being comprised between 94.35% and 104%. Ascorbic acid determination results obtained by cyclic voltammetry were compared with those obtained by the volumetric method with dichlorophenol indophenol. The results obtained by the two methods were in good agreement. PMID:19343183

Ascorbic acid deficiency in patients with lichen planus.

PubMed

Nicolae, Ilinca; Mitran, Cristina Iulia; Mitran, Madalina Irina; Ene, Corina Daniela; Tampa, Mircea; Georgescu, Simona Roxana

2017-01-01

Recent studies have highlighted the role of oxidative stress in the pathogenesis of lichen planus (LP). In the present study, the interest of the authors is focused on the investigation of ascorbic acid status in patients with LP and identification of parameters that might influence the level of this vitamin. We analyzed the level of urinary ascorbic acid (reflectometric method) in 77 patients with LP (cutaneous LP (CLP)-49 cases; oral LP (OLP)-28 cases) and 50 control subjects. The evaluation of all participants included clinical examination and laboratory and imaging tests. Compared to the control group (19.82 mg/dl) the level of ascorbic acid was significantly lower both in patients with CLP (8.47 mg/dl, p = 0.001) and in those with OLP (8.04 mg/dl, p = 0.001). In patients with LP it was found that the deficiency of ascorbic acid increases with age (r = -0.318, p = 0.032). The urinary concentrations of ascorbic acid were significantly lower in patients with LP associated with infections compared to patients with LP without infections. The urinary ascorbic acid level may be a useful parameter in identifying patients with LP who are at risk of developing viral or bacterial infections.

Effect of antibrowning dips and controlled atmosphere storage on the physico-chemical, visual and nutritional quality of minimally processed "Rojo Brillante" persimmons.

PubMed

Sanchís, Elena; Mateos, Milagros; Pérez-Gago, María B

2017-01-01

The combined effect of antibrowning dips and controlled atmosphere storage on fresh-cut "Rojo Brillante" persimmon quality was investigated. Persimmon slices were dipped in 10 g L -1 ascorbic acid, 10 g L -1 citric acid or water and were stored in different controlled atmospheres at 5 ℃. Controlled atmosphere conditions were 21 kPa O 2  + 10 kPa CO 2 (Atm-B), 21 kPa O 2  + 20 kPa CO 2 (Atm-C), 5 kPa O 2  + 10 kPa CO 2 (Atm-D) and 5 kPa O 2 in the absence of CO 2 (Atm-E). Air (Atm-A) was used as a control. Atmospheres with high CO 2 concentrations induced darkening, associated with a flesh disorder known as "internal flesh browning". Only the samples placed in Atm-E, and treated with 10 g L -1 ascorbic acid or 10 g L -1 citric acid, controlled enzymatic browning, reduced firmness loss and prevented the "internal flesh browning" disorder. The maximum limit of marketability was achieved in the samples treated with 10 g L -1 citric acid and stored in Atm-E for nine storage days at 5 ℃. The total vitamin C, free radical scavenging activity, total phenolic content and total carotenoids of the fresh-cut "Rojo Brillante" persimmons were affected by maturity stage at harvest, whereas antibrowning dips and controlled atmosphere storage had no clear effect. © The Author(s) 2016.

Role of ascorbic acid in the inhibition of polyphenol oxidase and the prevention of browning in different browning-sensitive Lactuca sativa var. capitata (L.) and Eruca sativa (Mill.) stored as fresh-cut produce.

PubMed

Landi, Marco; Degl'Innocenti, Elena; Guglielminetti, Lorenzo; Guidi, Lucia

2013-06-01

Polyphenol oxidase (PPO) and, to a minor extent, peroxidase (POD) represent the key enzymes involved in enzymatic browning, a negative process induced by cutting fresh-cut produce such as lettuce (Lactuca sativa) and rocket salad (Eruca sativa). Although ascorbic acid is frequently utilised as an anti-browning agent, its mechanism in the prevention of the browning phenomenon is not clearly understood. The activity of PPO and POD and their isoforms in lettuce (a high-browning and low-ascorbic acid species) and rocket salad (a low-browning and high-ascorbic species) was characterised. The kinetic parameters of PPO and in vitro ascorbic acid-PPO inhibition were also investigated. In rocket salad, PPO activity was much lower than that in lettuce and cutting induced an increase in PPO activity only in lettuce. Exogenous ascorbic acid (5 mmol L(-1)) reduced PPO activity by about 90% in lettuce. POD did not appear to be closely related to browning in lettuce. PPO is the main enzyme involved in the browning phenomenon; POD appears to play a minor role. The concentration of endogenous ascorbic acid in rocket salad was related to its low-browning sensitivity after cutting. In lettuce, the addition of ascorbic acid directly inhibited PPO activity. The results suggest that the high ascorbic acid content found in rocket salad plays an effective role in reducing PPO activity. © 2012 Society of Chemical Industry.

Lutein, Trolox, ascorbic acid and combination of Trolox with ascorbic acid can improve boar semen quality during cryopreservation.

PubMed

Varo-Ghiuru, Florin; Miclea, Ileana; Hettig, Andrea; Ladoşi, Ioan; Miclea, Vasile; Egerszegi, István; Zăhan, Marius

2015-01-01

Due to pour quality of cryopreserved boar semen, artificial innsemination with frozen-thawed semen is quite limited. Developing protocols of boar semen cryopreservation represents a priority but also a challange. The goal of the present study was to evaluate the antioxidant potential of lutein, Trolox, ascorbic acid, and certain combinations of Trolox with ascorbic acid on boar semen cryopreservation procedure. Antioxidants were added to lactose-egg yolk extender, containing a final concentration of 3% glycerol and 0.5% Equex-STM. Semen of six boars was cryopreserved using straw-freezing procedure. After cryopreservation semen was thawed and evaluated for motility, normal apical ridge (NAR), hypo-osmotic swelling test (HOST) and DNA fragmentation index (DFI). Data were analyzed by one-way ANOVA. The results showed better motility after thawing at the concentration of 10 μM lutein, 200 μM Trolox, 200 μM ascorbic acid and 400-200 μM Trolox and ascorbic acid. The supplementation on boar freezing extender with 10 μM lutein increased post-thawed motility, NAR and HOST values (P < 0.01), and decrease DFI (P < 0.05) in comparison with control group. Similar results were obtained using 400-200 μM Trolox and ascorbic acid, with better results in the case of DFI (P < 0.01). In comparison with the control group, a concentration of 200 μM Trolox and 200 μM ascorbic acid provided significant differences (P < 0.01) of motility and NAR. The analysis of sperm characteristics showed that lutein and the mix between Trolox and ascorbic acid used in boar semen cryopreservation can improve the quality of spermatozoa.

Free radicals mediate postshock contractile impairment in cardiomyocytes.

PubMed

Tsai, Min-Shan; Sun, Shijie; Tang, Wanchun; Ristagno, Giuseppe; Chen, Wen-Jone; Weil, Max Harry

2008-12-01

Previous studies demonstrated myocardial dysfunction after electrical shock and indicated it may be related to free radicals. Whether the free radicals are generated after electrical shock has not been documented at the cellular level. This study was to investigate whether electrical shock generates intracellular free radicals inside cardiomyocytes and to evaluate whether reducing intracellular free radicals by pretreatment of ascorbic acid would reduce the contractile dysfunction after electrical shock. Randomized prospective animal study. University affiliated research laboratory. Sprague-Dawley rats. Cardiomyocytes isolated from adult male rats were divided into four groups: (1) electrical shock alone; (2) electrical shock pretreated with ascorbic acid; (3) pretreated with ascorbic acid alone; and (4) control. Ascorbic acid (0.2 mM) was administrated in the perfusate of the ascorbic acid + electrical shock and ascorbic acid groups. A 2-J electrical shock was delivered to the electrical shock and ascorbic acid + electrical shock groups. DCFH-DA-loaded cardiomyocytes showed increased intracellular free radicals after electrical shock. The contractions and Ca2+ transients were recorded optically with fura-2 loading. Within 4 mins after electrical shock in the electrical shock group, the length shortening decreased from 8.4% +/- 2.5% to 5.6% +/- 3.4% (p = 0.000) and the Ca2+ transient decreased from 1.15 +/- 0.13 au to 1.08 +/- 0.1 au (p = 0.038). Compared with control, a significant difference in length shortening (p = 0.001) but not Ca2+ transient (p = 0.052) was noted. In the presence of ascorbic acid, electrical shock did not affect length shortening and Ca2+ transient. Electrical shock generates free radicals inside the cardiomyocyte, and causes contractile impairment and associated decrease of Ca transient. Administering ascorbic acid may improve such damage by eliminating free radicals.

Ascorbic Acid Alleviates Water Stress in Young Peach Trees and Improves Their Performance after Rewatering.

PubMed

Penella, Consuelo; Calatayud, Ángeles; Melgar, Juan C

2017-01-01

Exogenous application of biochemicals has been found to improve water stress tolerance in herbaceous crops but there are limited studies on deciduous fruit trees. The goal of this research was to study if ascorbic acid applications could improve physiological mechanisms associated with water stress tolerance in young fruit trees. Ascorbic acid was foliarly applied at a concentration of 250 ppm to water-stressed and well-watered peach trees (control) of two cultivars ('Scarletprince' and 'CaroTiger'). Trees received either one or two applications, and 1 week after the second application all trees were rewatered to field capacity. Upon rewatering, CO 2 assimilation and stomatal conductance of water-stressed 'Scarletprince' trees sprayed with ascorbic acid (one or two applications) were similar to those of well-irrigated trees, but water-stressed trees that had not received ascorbic acid did not recover photosynthetical functions. Also, water status in sprayed water-stressed 'Scarletprince' trees was improved to values similar to control trees. On the other hand, water-stressed 'CaroTiger' trees needed two applications of ascorbic acid to reach values of CO 2 assimilation similar to control trees but these applications did not improve their water status. In general terms, different response mechanisms to cope with water stress in presence of ascorbic acid were found in each cultivar, with 'Scarletprince' trees preferentially using proline as compatible solute and 'CaroTiger' trees relying on stomatal regulation. The application of ascorbic acid reduced cell membrane damage and increased catalase activity in water-stressed trees of both cultivars. These results suggest that foliar applications of ascorbic acid could be used as a management practice for improving water stress tolerance of young trees under suboptimal water regimes.

Ascorbic Acid Alleviates Water Stress in Young Peach Trees and Improves Their Performance after Rewatering

PubMed Central

Penella, Consuelo; Calatayud, Ángeles; Melgar, Juan C.

2017-01-01

Exogenous application of biochemicals has been found to improve water stress tolerance in herbaceous crops but there are limited studies on deciduous fruit trees. The goal of this research was to study if ascorbic acid applications could improve physiological mechanisms associated with water stress tolerance in young fruit trees. Ascorbic acid was foliarly applied at a concentration of 250 ppm to water-stressed and well-watered peach trees (control) of two cultivars (‘Scarletprince’ and ‘CaroTiger’). Trees received either one or two applications, and 1 week after the second application all trees were rewatered to field capacity. Upon rewatering, CO2 assimilation and stomatal conductance of water-stressed ‘Scarletprince’ trees sprayed with ascorbic acid (one or two applications) were similar to those of well-irrigated trees, but water-stressed trees that had not received ascorbic acid did not recover photosynthetical functions. Also, water status in sprayed water-stressed ‘Scarletprince’ trees was improved to values similar to control trees. On the other hand, water-stressed ‘CaroTiger’ trees needed two applications of ascorbic acid to reach values of CO2 assimilation similar to control trees but these applications did not improve their water status. In general terms, different response mechanisms to cope with water stress in presence of ascorbic acid were found in each cultivar, with ‘Scarletprince’ trees preferentially using proline as compatible solute and ‘CaroTiger’ trees relying on stomatal regulation. The application of ascorbic acid reduced cell membrane damage and increased catalase activity in water-stressed trees of both cultivars. These results suggest that foliar applications of ascorbic acid could be used as a management practice for improving water stress tolerance of young trees under suboptimal water regimes. PMID:28979284

Determination of the ascorbic acid content of two medicinal plants in Nigeria.

PubMed

H A, Okeri; P O, Alonge

2006-01-01

The fresh and dried leaves of two edible plants, Oldenlandia corymbosa and Dissotis rotundifolia have been assayed for their ascorbic acid content. They were found to be rich sources of ascorbic acid (vitamin C) when compared with some common garden fruits and vegetables. Students' t-test statistical analysis using INSTAT.EXE program for the results (mean+/-SEM) shows that there was no significant difference for the fresh leaves of the individual plants and also there is no significant difference for the dried leaves (P=0.05). However, there was significant difference between ascorbic acid content of the fresh and dried leaves of the same plant, obviously indicating that the fresh leaves contain more ascorbic acid than the dried leaves.

21 CFR 172.315 - Nicotinamide-ascorbic acid complex.

Code of Federal Regulations, 2013 CFR

2013-04-01

... (CONTINUED) FOOD FOR HUMAN CONSUMPTION (CONTINUED) FOOD ADDITIVES PERMITTED FOR DIRECT ADDITION TO FOOD FOR HUMAN CONSUMPTION Special Dietary and Nutritional Additives § 172.315 Nicotinamide-ascorbic acid complex...: (a) The additive is the product of the controlled reaction between ascorbic acid and nicotinamide...

21 CFR 172.315 - Nicotinamide-ascorbic acid complex.

Code of Federal Regulations, 2012 CFR

2012-04-01

... (CONTINUED) FOOD FOR HUMAN CONSUMPTION (CONTINUED) FOOD ADDITIVES PERMITTED FOR DIRECT ADDITION TO FOOD FOR HUMAN CONSUMPTION Special Dietary and Nutritional Additives § 172.315 Nicotinamide-ascorbic acid complex...: (a) The additive is the product of the controlled reaction between ascorbic acid and nicotinamide...

Effect of ascorbic acid postharvest treatment on enzymatic browning, phenolics and antioxidant capacity of stored mung bean sprouts.

PubMed

Sikora, Małgorzata; Świeca, Michał

2018-01-15

Enzymatic browning limits the postharvest life of minimally processed foods, thus the study selected the optimal inhibitors of polyphenol oxidase (PPO) and evaluated their effect on enzymatic browning, phenolics and antioxidant capacity of stored mung bean sprouts. The sprouts treated with 2mM and 20mM ascorbic acid had a lowered PPO activity; compared to the control by 51% and 60%, respectively. The inhibition was reflected in a significant decrease in enzymatic browning. The sprouts treated with 20mM ascorbic acid had 22% and 23% higher phenolic content after 3 and 7days of storage, respectively. Both storage and ascorbic acid treatment increased potential bioaccessibility of phenolics. Generally, there was no effect of the treatments on the antioxidant capacity; however, a significant increase in the reducing potential was determined for the sprouts washed with 20mM ascorbic acid. In conclusion, ascorbic acid treatments may improve consumer quality of stored sprouts. Copyright © 2017 Elsevier Ltd. All rights reserved.

The co-pigmentation of anthocyanin isolated from mangosteen pericarp (Garcinia Mangostana L.) as Natural Dye for Dye- Sensitized Solar Cells (DSSC)

NASA Astrophysics Data System (ADS)

Munawaroh, H.; adillah, G. F.; Saputri, L. N. M. Z.; Hanif, Q. A.; Hidayat, R.; Wahyuningsih, S.

2016-02-01

Study of color stability of anthocyanin from extract mangosteen pericarp (Garcinia mangostana L.) with co-pigmentation method has been conducted. Malic acid and ascorbic acid used as a co-pigment to stabilize the anthocyanin structure through formation of new binding between anthocyanin. Anthocyanin from mangosteen pericarp were isolated by several steps, including maceration, extraction, and Thin Layer Chromatography (TLC). The anthocyanin separation was conducted by TLC, while the identification of functional groups of those compound, were used FTIR (Fourier Transform Infrared Spectroscopy) for spectra analysis. Ultraviolet- visible absorption spectra have represented differences absorbance and color intensity in various pH. Copigmentation with malic acid and ascorbic acid in many composition and temperature were also well described. Meanwhile, anthocyanin-malic acid and anthocyanin-ascorbic acid have color retention higher than that of pure anthocyanin. Maximum color retention has been achieved at a ratio of 1:3 and 1:5 for ascorbic acid and malic acid, respectively. Therefore, the addition of ascorbic acid and malic acid as a copigment shows the ability to protect color retention of anthocyanin (mangosteen pericarp) from degradation process. The better efficiency of DSSC (η) have been achieved, whereas n of controlled anthocyanin, anthocyanin-ascorbic acid, and anthocyanin-malic acid were 0,1996%, 0,2922%, 0,3029%, respectively.

New evidence for antioxidant properties of vitamin C.

PubMed

Vojdani, A; Bazargan, M; Vojdani, E; Wright, J

2000-01-01

This study was designed to examine the effect of 500 to 5,000 mg of ascorbic acid on DNA adducts, natural killer (NK) cell activity, programmed cell death, and cell cycle analysis of human peripheral blood leukocytes. According to our hypothesis, if ascorbic acid is a pro-oxidant, doses between 500 and 5,000 mg should enhance DNA adduct formation, decrease immune function, change the cell cycle progression, and increase the rate of apoptosis. Twenty healthy volunteers were divided into four groups and given either placebo or daily doses of 500, 1,000 or 5,000 mg of ascorbic acid for a period of 2 weeks. On days 0, 1, 7, 15, and 21, blood was drawn from them, and the leukocytes were separated and examined for intracellular levels of ascorbic acid, the level of 8-hydroxyguanosine, NK cell activity, cell cycle progression, and apoptosis. Depending on the subjects, between a 0% and a 40% increase in cellular absorption of ascorbic acid was observed when daily doses of 500 mg were used. At doses greater than 500 mg, this cellular absorption was not increased further, and all doses produced equivalent increases in ascorbic acid on days 1 to 15. This increase in cellular concentration of ascorbic acid resulted in no statistically meaningful changes in the level of 8-hydroxyguanosine, increased NK cytotoxic activity, a reduced percentage of cells undergoing apoptosis, and switched cell cycle phases from S and G2/M to G0/G1. After a period of 1 week, with no placebo or vitamin washout, ascorbic acid levels along with functional assays returned to the baseline and became equivalent to placebos. In comparison with baseline values, no change (not more than daily assays variation) was seen in ascorbate concentrations or other assays during oral placebo treatment. We concluded that ascorbic acid is an antioxidant and that doses up to 5,000 mg neither induce mutagenic lesions nor have negative effects on NK cell activity, apoptosis, or cell cycle.

Assessment of Antioxidant and Cytotoxicity Activities of Saponin and Crude Extracts of Chlorophytum borivilianum

PubMed Central

Abd Aziz, Maheran; Stanslas, Johnson; Abdul Kadir, Mihdzar

2013-01-01

The present paper focused on antioxidant and cytotoxicity assessment of crude and total saponin fraction of Chlorophytum borivilianum as an important medicinal plant. In this study, three different antioxidant activities (2,2-diphenyl-1-picrylhydrazyl radical scavenging (DPPH), ferrous ion chelating (FIC), and β-carotene bleaching (BCB) activity) of crude extract and total saponin fraction of C. borivilianum tubers were performed. Crude extract was found to possess higher free radical scavenging activity (ascorbic acid equivalents 2578 ± 111 mg AA/100 g) and bleaching activity (IC50 = 0.7 mg mL−1), while total saponin fraction displayed higher ferrous ion chelating (EC50 = 1 mg mL−1). Cytotoxicity evaluation of crude extract and total saponin fraction against MCF-7, PC3, and HCT-116 cancer cell lines using 3-(4,5-dimethylthiazol-2-yl)-2,5 diphenyltetrazolium bromide (MTT) cell viability assay indicated a higher cytotoxicity activity of the crude extract than the total saponin fraction on all cell lines, being most effective and selective on MCF-7 human breast cancer cell line. PMID:24223502

Extraction, characterization and biological studies of phytochemicals from Mammea suriga.

PubMed

Poojary, Mahesha M; Vishnumurthy, Kanivebagilu A; Vasudeva Adhikari, Airody

2015-06-01

The present work involves extraction of phytochemicals from the root bark of a well-known Indian traditional medicinal plant, viz. Mammea suriga , with various solvents and evaluation of their in vitro antimicrobial and antioxidant activities using standard methods. The phytochemical analysis indicates the presence of some interesting secondary metabolites like flavonoids, cardiac glycosides, alkaloids, saponins and tannins in the extracts. Also, the solvent extracts displayed promising antimicrobial activity against Staphylococcus aureus , Bacillus subtilis and Cryptococcus neoformans with inhibition zone in a range of 20-33 mm. Further, results of their antioxidant screening revealed that aqueous extract (with IC 50 values of 111.51±1.03 and 31.05±0.92 μg/mL in total reducing power assay and DPHH radical scavenging assay, respectively) and ethanolic extract (with IC 50 values of 128.00±1.01 and 33.25±0.89 μg/mL in total reducing power assay and DPHH radical scavenging assay, respectively) were better antioxidants than standard ascorbic acid. Interestingly, FT-IR analysis of each extract established the presence of various biologically active functional groups in it.

Antioxidative activities of hydrolysates from edible birds nest using enzymatic hydrolysis

NASA Astrophysics Data System (ADS)

Muhammad, Nurul Nadia; Babji, Abdul Salam; Ayub, Mohd Khan

2015-09-01

Edible bird's nest protein hydrolysates (EBN) were prepared via enzymatic hydrolysis to investigate its antioxidant activity. Two types of enzyme (alcalase and papain) were used in this study and EBN had been hydrolysed with different hydrolysis time (30, 60, 90 and 120 min). Antioxidant activities in EBN protein hydrolysate were measured using DPPH, ABTS+ and Reducing Power Assay. From this study, increased hydrolysis time from 30 min to 120 min contributed to higher DH, as shown by alcalase (40.59%) and papain (24.94%). For antioxidant assay, EBN hydrolysed with papain showed higher scavenging activity and reducing power ability compared to alcalase. The highest antioxidant activity for papain was at 120 min hydrolysis time with ABTS (54.245%), DPPH (49.78%) and Reducing Power (0.0680). Meanwhile for alcalase, the highest antioxidant activity was at 30 min hydrolysis time. Even though scavenging activity for EBN protein hydrolysates were high, the reducing power ability was quite low as compared to BHT and ascorbic Acid. This study showed that EBN protein hydrolysate with alcalase and papain treatments potentially exhibit high antioxidant activity which have not been reported before.

Formation of protein sub-visible particles during vacuum degassing of etanercept solutions.

PubMed

Wang, Haibin; Zheng, Hong-Jian; Wang, Zhao; Bai, Hua; Carpenter, John F; Chen, Shuqing; Fang, Wei-Jie

2014-05-01

The main purpose of this manuscript is to describe a phenomenon in which vacuum degassing a reconstituted freeze-dried fusion protein etanercept formulation caused a significant amount of protein sub-visible particles (SbVP). Physical stability of etanercept was monitored by micro-flow imaging (MFI), dynamic light scattering (DLS), size-exclusion high pressure liquid chromatography (SE-HPLC) and far- and near-ultraviolet circular dichroism (far- and near-UV CD). One potential explanation of this phenomenon is that bubble collapses when the vacuum is applied, leads to substantial heat formation, and ultimately free radical formation. Subsequently, the effect of a free-radical scavenger (ascorbic acid, AA) on SbVP formation was also evaluated. Degassing of etanercept solution by applying vacuum caused substantial increase of SbVP, as detected by MFI and DLS. However, traditional techniques such as SE-HPLC could not detect any change. The addition of free-radical scavenger had minimal effect on SbVP formation, therefore the formation of free radicals was probably not the main cause for this effect. Copyright © 2014 Elsevier B.V. All rights reserved.

Enhanced antioxidant activity of gold nanoparticle embedded 3,6-dihydroxyflavone: a combinational study

NASA Astrophysics Data System (ADS)

Medhe, Sharad; Bansal, Prachi; Srivastava, Man Mohan

2014-02-01

The antioxidative effect of selected dietary compounds (3,6-dihydroxyflavone, lutein and selenium methyl selenocysteine) was determined in single and combination using DPPH (2,2-diphenyl-l-picrylhydrazyl), OH (hydroxyl), H2O2 (hydrogen peroxide) and NO (nitric oxide) radical scavenging assays. Radical scavenging effect of the dietary phytochemicals individually are found to be in the order: ascorbic acid (standard) > lutein > 3,6-dihydroxyflavone > selenium methyl selenocysteine, at concentration 100 μg/ml, confirmed by all the four bioassays (p < 0.05). Among the various combinations studied, the triplet combination of 3,6-dihydroxyflavone, lutein and selenium methyl selenocysteine (1:1:1), exhibited enhancement in the target activity at same concentration level. Synthesized gold nanoparticle embedded 3,6-dihydroxyflavone further enhanced the target antioxidant activity. The combinational study including gold nanoparticle embedded 3,6-dihydroxyflavone with other native dietary nutrients showed remarkable increase in antioxidant activity at the same concentration level. The present in vitro study on combinational and nanotech enforcement of dietary phytochemicals shows the utility in the architecture of nanoparticle embedded phytoproducts having a wide range of applications in medical science.

[Ascorbic acid consumption and serum levels in smokers and non-smokers adult men in Hermosillo, Sonora, México].

PubMed

Méndez, Rosa Olivia; Wyatt, C Jane; Saavedra, Javier; Ornelas, Alicia

2002-12-01

Ascorbic acid is one of the important antioxidant nutrients that can aid in the prevention of oxidative cellular damage. Adequate dietary intake is essential as humans can not synthesize this vitamin. It has been reported that smokers require higher dietary intakes to maintain their serum levels. The objective of this study was to determine serum levels of ascorbic acid in young male smokers and non smokers in the city of Hermosillo, Sonora, Mexico. In addition, their dietary intake of ascorbic acid was determined by a 24 h dietary recall. The dietary intake of ascorbic acid in 12 smokers was 64 +/- 11 mg/d and in 13 non smokers it was 70 +/- 12 mg/d. The smokers in this study did not meet the dietary recommendation of 100 mg/d. Serum ascorbic acid values in smokers and non smokers were 24.2 +/- 6.9 mumol/L and 30.9 +/- 3.7 mumol/L respectively. No significant difference was found among the 2 groups. Although the average serum ascorbic acid values fell within the range considered normal, 50% of the smokers had individual values that were below 23 mumol/L, indicating that these subjects have hipovitaminosis. A positive correlation between intake and serum levels was obtained for smokers (r = 0.71; p = 0.03). The results of this study suggest smokers may be at increased risk for chronic diseases due to their low intake and low serum levels of ascorbic acid.

Individual and combined effects of fluoranthene, phenanthrene, mannitol and sulfuric acid on marigold (Calendula officinalis).

PubMed

Khpalwak, Wahdatullah; Abdel-Dayem, Sherif M; Sakugawa, Hiroshi

2018-02-01

A study was conducted to characterize marigold stress response to polycyclic aromatic hydrocarbons (PAHs) (oxidative stress inducers) with and without sulfuric acid (S.Acid; pH 3) (acid-stress inducer), and to evaluate reactive oxygen species (ROS) scavenging activity of mannitol (Mann). Marigold (Calendula officinalis) seedlings were grown in a greenhouse and fumigated with fluoranthene (FLU), phenanthrene (PHE), Mann, and S.Acid individually and in various combinations for 40 days. Various physiological and biochemical parameters among others were analyzed using standard methods. The results revealed that fumigation of FLU induced oxidative stress to the plants via ROS generation leading to negative effects on photosynthesis at near saturating irradiance (A max ), stomatal conductance (G s ), internal carbon dioxide concentration (C i ), leaf water relations and chlorophyll pigments. Significant per cent inhibition of A max (54%), G s (86%) and C i (32%), as well as per cent reductions in chlorophyll a (Chl.a) (33%), Chl.b (34%), and total chlorophyll (Tot. Chl) (48%) contents were recorded in FLU fumigated treatment in comparison to control. Combination of Mann with FLU scavenged the generated ROS and substantially lowered the oxidative stress on the plants hence all the measured parameters were not significantly different from control. PHE fumigation had varied effects on marigold plants and was not as deleterious as FLU. Combined fumigation of S.Acid with both the PAHs had significant negative effect on leaf water relations, and positive effect on fresh and turgid weight of the plants but had no effect on the other measured parameters. The lowest proline contents and highest catalase and ascorbate peroxidase activities in FLU fumigated plants further confirmed that oxidative stress was imposed via the generation of ROS. From the results, it is evident that Mann could be an efficient scavenger of ROS-generated by FLU in the marigold plants. We recommend Mann to be widely used for the protection of higher plants from FLU-generated stress in the urban areas. Copyright © 2017 Elsevier Inc. All rights reserved.

Kinetics of ascorbic acid degradation in un-pasteurized Iranian lemon juice during regular storage conditions.

PubMed

Abbasi, A; Niakousari, M

2008-05-15

The aim of this research was to determine shelf life stability of un-pasteurized lemon juice filled in clear or dark green glass bottles. Presence of light, time and temperature affect the ascorbic acid retention in citrus juices. Bottles were stored at room temperature (27 +/- 3 degrees C) and in the refrigerator (3 +/- 1 degrees C). Total soluble solids, total titrable acidity and pH value were measured every three weeks and analysis was carried out on ascorbic acid content by means of titration method in the presence of 2,6-dichlorophenol indophenol. The study was carried out for 12 weeks after which slight changes in color, taste and apparent texture in some samples were observed and ascorbic acid content reduced by 50%. Soluble solids content, pH value and total acidity were 5.5 degrees Brix, 2.73 and 5 g/100 mL, respectively which appeared not to be significantly influenced by storage time or conditions. Ascorbic acid content initially at 38.50 mg/100 mL was sharply reduced to about 22 mg/100 mL within the first three weeks of storage. The final ascorbic acid content of all samples was about 15 mg/100 mL. The deteriorative reaction of ascorbic acid in the juice at all conditions followed a first-order kinetic model with activation energy of 137 cal mol(-1).

21 CFR 172.315 - Nicotinamide-ascorbic acid complex.

Code of Federal Regulations, 2014 CFR

2014-04-01

... (CONTINUED) FOOD ADDITIVES PERMITTED FOR DIRECT ADDITION TO FOOD FOR HUMAN CONSUMPTION Special Dietary and Nutritional Additives § 172.315 Nicotinamide-ascorbic acid complex. Nicotinamide-ascorbic acid complex may be safely used in accordance with the following prescribed conditions: (a) The additive is the product of...

Chemical repair activity of free radical scavenger edaravone: reduction reactions with dGMP hydroxyl radical adducts and suppression of base lesions and AP sites on irradiated plasmid DNA

PubMed Central

Hata, Kuniki; Urushibara, Ayumi; Yamashita, Shinichi; Lin, Mingzhang; Muroya, Yusa; Shikazono, Naoya; Yokoya, Akinari; Fu, Haiying; Katsumura, Yosuke

2015-01-01

Reactions of edaravone (3-methyl-1-phenyl-2-pyrazolin-5-one) with deoxyguanosine monophosphate (dGMP) hydroxyl radical adducts were investigated by pulse radiolysis technique. Edaravone was found to reduce the dGMP hydroxyl radical adducts through electron transfer reactions. The rate constants of the reactions were greater than 4 × 108 dm3 mol−1 s−1 and similar to those of the reactions of ascorbic acid, which is a representative antioxidant. Yields of single-strand breaks, base lesions, and abasic sites produced in pUC18 plasmid DNA by gamma ray irradiation in the presence of low concentrations (10–1000 μmol dm−3) of edaravone were also quantified, and the chemical repair activity of edaravone was estimated by a method recently developed by the authors. By comparing suppression efficiencies to the induction of each DNA lesion, it was found that base lesions and abasic sites were suppressed by the chemical repair activity of edaravone, although the suppression of single-strand breaks was not very effective. This phenomenon was attributed to the chemical repair activity of edaravone toward base lesions and abasic sites. However, the chemical repair activity of edaravone for base lesions was lower than that of ascorbic acid. PMID:25212600

Interaction of gold nanoparticles with free radicals and their role in enhancing the scavenging activity of ascorbic acid.

PubMed

Razzaq, Humaira; Saira, Farhat; Yaqub, Azra; Qureshi, Rumana; Mumtaz, Misbah; Saleemi, Samia

2016-08-01

The present study investigates the interaction of citrate stabilized gold nanoparticles (12±1.5nm) (GNPs) with free radicals; 1,1-diphenyl-2-picrylhydrazyl (DPPH) stable and electrochemically generated superoxide, O2(-). Different experiments were designed to understand the interaction between GNPs and DPPH by employing cyclic voltammetry, UV-vis spectroscopy and computational chemistry using 6-311G basis set. The increase in heterogeneous rate constant, ksh, of DPPH upon addition of GNPs pointed towards possible complex formation, DPPH-GNPs which were further explained by a model assuming surface adsorption of DPPH on GNPs. Further, the model was validated by studying interaction of GNPs with a biologically important free radical, O2(-). Exciting result in terms of disappearance of anodic peak after GNPs addition confirmed that gold nanoparticles interacted with stable as well as unstable free radicals. Also, the stoichiometry of the most stable complex GNP-DPPH was determined from UV-vis spectroscopy by applying Job's method. The GNP-DPPH complex was found to be active with 46.0% reduction of the IC50 value of standard antioxidant, ascorbic acid (AA), indicating its role in enhancing antioxidant activity. Hence, this study presents a simple and potential approach to enhance the efficiency of natural antioxidants without modifying their structure, or involving the complex functionalization of GNPs with antioxidants. Copyright © 2016. Published by Elsevier B.V.

Laser light and magnetic field stimulation effect on biochemical, enzymes activities and chlorophyll contents in soybean seeds and seedlings during early growth stages.

PubMed

Asghar, Tehseen; Jamil, Yasir; Iqbal, Munawar; Zia-Ul-Haq; Abbas, Mazhar

2016-12-01

Laser and magnetic field bio-stimulation attracted the keen interest of scientific community in view of their potential to enhance seed germination, seedling growth, physiological, biochemical and yield attributes of plants, cereal crops and vegetables. Present study was conducted to appraise the laser and magnetic field pre-sowing seed treatment effects on soybean sugar, protein, nitrogen, hydrogen peroxide (H 2 O 2 ) ascorbic acid (AsA), proline, phenolic and malondialdehyde (MDA) along with chlorophyll contents (Chl "a" "b" and total chlorophyll contents). Specific activities of enzymes such as protease (PRT), amylase (AMY), catalyst (CAT), superoxide dismutase (SOD) and peroxides (POD) were also assayed. The specific activity of enzymes (during germination and early growth), biochemical and chlorophyll contents were enhanced significantly under the effect of both laser and magnetic pre-sowing treatments. Magnetic field treatment effect was slightly higher than laser treatment except PRT, AMY and ascorbic acid contents. However, both treatments (laser and magnetic field) effects were significantly higher versus control (un-treated seeds). Results revealed that laser and magnetic field pre-sowing seed treatments have potential to enhance soybean biological moieties, chlorophyll contents and metabolically important enzymes (degrade stored food and scavenge reactive oxygen species). Future study should be focused on growth characteristics at later stages and yield attributes. Copyright © 2016 Elsevier B.V. All rights reserved.

Novel hydroxyl radical scavenging antioxidant activity assay for water-soluble antioxidants using a modified CUPRAC method.

PubMed

Bektaşoğlu, Burcu; Esin Celik, Saliha; Ozyürek, Mustafa; Güçlü, Kubilay; Apak, Reşat

2006-07-07

Reactive oxygen species (ROS) such as superoxide anion, hydroxyl ((*)OH), peroxyl, and alkoxyl radicals may attack biological macromolecules giving rise to oxidative stress-originated diseases. Since (*)OH is very short-lived, secondary products resulting from (*)OH attack to various probes are measured. Although the measurement of aromatic hydroxylation with HPLC/electrochemical detection is more specific than the low-yield TBARS test, it requires sophisticated instrumentation. As a more convenient and less costly alternative, we used p-aminobenzoate, 2,4- and 3,5-dimethoxybenzoate probes for detecting hydroxyl radicals generated from an equivalent mixture of Fe(II)+EDTA with hydrogen peroxide. The produced hydroxyl radicals attacked both the probe and the water-soluble antioxidants in 37 degrees C-incubated solutions for 2h. The CUPRAC (i.e., our original method for total antioxidant capacity assay) absorbance of the ethylacetate extract due to the reduction of Cu(II)-neocuproine reagent by the hydroxylated probe decreased in the presence of (*)OH scavengers, the difference being proportional to the scavenging ability of the tested compound. A rate constant for the reaction of the scavenger with hydroxyl radical can be deduced from the inhibition of color formation. The second-order rate constants of the scavengers were determined with competition kinetics by means of a linear plot of A(0)/A as a function of C(scavenger)/C(probe), where A(0) and A are the CUPRAC absorbances of the system in the absence and presence of scavenger, respectively, and C is the molar concentration of relevant species. The 2,4- and 3,5-dimethoxybenzoates were the best probes in terms of linearity and sensitivity. Iodide, metabisulfite, hexacyanoferrate(II), thiourea, formate, and dimethyl sulfoxide were shown by the modified CUPRAC assay to be more effective scavengers than mannitol, glucose, lysine, and simple alcohols, as in the TBARS assay. The developed method is less lengthy, more specific, and of a higher yield than the classical TBARS assay. The hydroxyl radical scavenging rate constants of ascorbic acid, formate, and hexacyanoferrate(II) that caused interference in other assays could be easily found with the proposed procedure.

Enzymatic synthesis of 3-O-α-maltosyl-l-ascorbate using an engineered cyclodextrin glucanotransferase.

PubMed

Ahn, Hee-Jeong; Li, Chao; Cho, Hye-Bin; Park, Sunghoon; Chang, Pahn-Shick; Kim, Young-Wan

2015-02-15

A mutant derived from a cyclodextrin glucantransferase with an alanine residue as its acid/base catalyst residue (CGT-E284A) catalyzed regioselective glycosylation at 3-OH of l-ascorbic acid using α-maltosyl fluoride (αG2F) and l-ascorbic acid as the donor and acceptor, respectively, yielding 3-O-α-maltosyl-l-ascorbate (AA3αG2). The optimum conditions were determined by high-performance liquid chromatography analysis with 20mM αG2F and 40mM l-ascorbic acid as the substrates at pH 7.5 and 25°C with 1mg/ml of the enzyme for 24h. Calcium ions bound in CGT-E284A played an important role in the transglycosylation. CGT-E284A exhibited typical saturation kinetic behaviour for αG2F at a fixed acceptor concentration (40mM), and substrate inhibition by l-ascorbic acid was observed at high l-ascorbic acid concentrations (>60mM). AA3αG2 was isolated from a preparative scale reaction with a yield of 29%, and it showed extremely high stability under oxidative conditions. Copyright © 2014 Elsevier Ltd. All rights reserved.

Anemia Causes Hypoglycemia in Intensive Care Unit Patients Due to Error in Single-Channel Glucometers: Methods of Reducing Patient Risk

DTIC Science & Technology

2010-01-01

hematocrit, low oxygen tension, acetaminophen, uric acid , ascorbic acid , maltose, galactose, xy- lose, lactose, operator inexperience, age of strips, heat...Biomedical, Waltham, MA) that corrects for the effects of anemia, low oxygen tension, acetaminophen, uric acid , ascorbic acid , maltose, galactose, xylose, and...resulted in inappropriately high glucometer values (data not shown). The effects of interfering substances (acetaminophen, uric acid , ascorbic acid

21 CFR 182.8013 - Ascorbic acid.

Code of Federal Regulations, 2012 CFR

2012-04-01

... 21 Food and Drugs 3 2012-04-01 2012-04-01 false Ascorbic acid. 182.8013 Section 182.8013 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) FOOD FOR HUMAN CONSUMPTION (CONTINUED) SUBSTANCES GENERALLY RECOGNIZED AS SAFE Nutrients § 182.8013 Ascorbic acid. (a...

21 CFR 182.8013 - Ascorbic acid.

Code of Federal Regulations, 2010 CFR

2010-04-01

... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Ascorbic acid. 182.8013 Section 182.8013 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) FOOD FOR HUMAN CONSUMPTION (CONTINUED) SUBSTANCES GENERALLY RECOGNIZED AS SAFE Nutrients § 182.8013 Ascorbic acid. (a...

21 CFR 182.8013 - Ascorbic acid.

Code of Federal Regulations, 2011 CFR

2011-04-01

... 21 Food and Drugs 3 2011-04-01 2011-04-01 false Ascorbic acid. 182.8013 Section 182.8013 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) FOOD FOR HUMAN CONSUMPTION (CONTINUED) SUBSTANCES GENERALLY RECOGNIZED AS SAFE Nutrients § 182.8013 Ascorbic acid. (a...

21 CFR 182.8013 - Ascorbic acid.

Code of Federal Regulations, 2013 CFR

2013-04-01

... 21 Food and Drugs 3 2013-04-01 2013-04-01 false Ascorbic acid. 182.8013 Section 182.8013 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) FOOD FOR HUMAN CONSUMPTION (CONTINUED) SUBSTANCES GENERALLY RECOGNIZED AS SAFE Nutrients § 182.8013 Ascorbic acid. (a...

Nutritional aspects of ascorbic acid: uses and abuses.

PubMed

Vilter, R W

1980-12-01

Ascorbic acid in physiological doses is essential for the normal functioning of the human body. Larger doses are required to treat a severe deficiency of vitamin C intake, as in the case of scurvy. Occasionally, massive doses may be required to treat a metabolic defect involving ascorbic acid. There has been some mention of megadose therapy with ascorbic acid for the prevention of colds, the improved healing of wounds and even the treatment of cancer, but no acceptable scientific data have been presented. In fact, in a few instances, such therapy has proved injurious.

Diffusive properties of Vitamin C aqueous solutions by quasielastic neutron scattering

NASA Astrophysics Data System (ADS)

Migliardo, F.; Magazù, S.; Migliardo, P.

2001-07-01

Quasi elastic neutron scattering (QENS) results on aqueous solutions of L-ascorbic acid (Vitamin C) are reported. Data, collected by the IRIS spectrometer at the ISIS facility on partially deuterated L-ascorbic acid in D 2O and on hydrogenated L-ascorbic acid in H 2O, allow to characterize the diffusive dynamics of both hydrated Vitamin C and water, revealing that this latter is strongly affected by the presence of L-ascorbic acid and furnishing a hydration number value of ∼5 at T=33°C.

Ascorbic acid and sodium benzoate synergistically aggravates testicular dysfunction in adult Wistar rats.

PubMed

Kehinde, Olaniyi S; Christianah, Oyewopo I; Oyetunji, Oyewopo A

2018-01-01

The effect of the concomitant use of sodium benzoate (NaB) and ascorbic acid on human health remains controversial. Therefore, the current study is designed to investigate the effect of NaB and ascorbic acid on the testicular function of adult Wistar rats. Adult Wistar rats were randomly allotted into Control (vehicle; received 1 ml of distilled water), NaB-treated (SB-treated; received 100 mg/kg body weight; b.w ), ascorbic acid-treated (AA-treated; received 150 mg/kg b.w ) and NaB+ ascorbic acid-treated (SB+AA-treated) groups. The treatment lasted for 28 days and the administration was given orally. The body weight change was monitored. Semen analysis, biochemical assay and histological examination were performed. Treatment with NaB significantly altered the cytoarchitecture of testicular tissue, sperm quality, testicular endocrine function and oxidative stress status without any alteration in body weight gain compared to control. In addition, treatment with NaB+ ascorbic acid exacerbated testicular tissue disruption, impaired sperm quality and testicular endocrine impairment with significant reduction in oxidative stress and unaltered body weight gain when compared with NaB-treated group. This study suggests that ascorbic acid and NaB synergistically aggravates testicular dysfunction. This is independent of oxidative stress status.

Variation in the SLC23A1 gene does not influence cardiometabolic outcomes to the extent expected given its association with L-ascorbic acid.

PubMed

Wade, Kaitlin H; Forouhi, Nita G; Cook, Derek G; Johnson, Paul; McConnachie, Alex; Morris, Richard W; Rodriguez, Santiago; Ye, Zheng; Ebrahim, Shah; Padmanabhan, Sandosh; Watt, Graham; Bruckdorfer, K Richard; Wareham, Nick J; Whincup, Peter H; Chanock, Stephen; Sattar, Naveed; Lawlor, Debbie A; Davey Smith, George; Timpson, Nicholas J

2015-01-01

Observational studies showed that circulating L-ascorbic acid (vitamin C) is inversely associated with cardiometabolic traits. However, these studies were susceptible to confounding and reverse causation. We assessed the relation between L-ascorbic acid and 10 cardiometabolic traits by using a single nucleotide polymorphism in the solute carrier family 23 member 1 (SLC23A1) gene (rs33972313) associated with circulating L-ascorbic acid concentrations. The observed association between rs33972313 and cardiometabolic outcomes was compared with that expected given the rs33972313-L-ascorbic acid and L-ascorbic acid-outcome associations. A meta-analysis was performed in the following 5 independent studies: the British Women's Heart and Health Study (n = 1833), the MIDSPAN study (n = 1138), the Ten Towns study (n = 1324), the British Regional Heart Study (n = 2521), and the European Prospective Investigation into Cancer (n = 3737). With the use of a meta-analysis of observational estimates, inverse associations were shown between L-ascorbic acid and systolic blood pressure, triglycerides, and the waist-hip ratio [the strongest of which was the waist-hip ratio (-0.13-SD change; 95% CI: -0.20-, -0.07-SD change; P = 0.0001) per SD increase in L-ascorbic acid], and a positive association was shown with high-density lipoprotein (HDL) cholesterol. The variation at rs33972313 was associated with a 0.18-SD (95% CI: 0.10-, 0.25-SD; P = 3.34 × 10⁻⁶) increase in L-ascorbic acid per effect allele. There was no evidence of a relation between the variation at rs33972313 and any cardiometabolic outcome. Although observed estimates were not statistically different from expected associations between rs33972313 and cardiometabolic outcomes, estimates for low-density lipoprotein cholesterol, HDL cholesterol, triglycerides, glucose, and body mass index were in the opposite direction to those expected. The nature of the genetic association exploited in this study led to limited statistical application, but despite this, when all cardiometabolic traits were assessed, there was no evidence of any trend supporting a protective role of L-ascorbic acid. In the context of existing work, these results add to the suggestion that observational relations between L-ascorbic acid and cardiometabolic health may be attributable to confounding and reverse causation.

Stress-induced ascorbic acid depletion and cortisol production in two salmonid fishes

USGS Publications Warehouse

Wedemeyer, Gary

1969-01-01

Interrenal ascorbic acid and serum cortisol were measured in non-specificity stressed yearling coho salmon and rainbow trout.Interrenal ascorbate was markedly decreased during stress but increased to normal if adaptation occurred.Serum cortisol was elevated by non-specific stress and remained high after interrenal ascorbate had returned to initial levels.

In vitro evaluation of the antioxidant potential, phenolic and flavonoid contents of the stem bark ethanol extract of Anogeissus leiocarpus.

PubMed

Olugbami, J O; Gbadegesin, M A; Odunola, O A

2014-09-01

Plant-derived antioxidants with free radical scavenging activities can be relevant as chemopreventive agents against the numerous diseases associated with free radicals and reactive oxygen species. Some phytoconstituents possess antioxidant activities in biological systems. On this basis, we evaluated the antioxidant potential, and determined the total phenolic and flavonoid contents of the e thanol e xtract of the s tem bark of A nogeissus l eiocarpus [ EESAL ]. Antioxidant assays carried out include: 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging, phosphomolybdate, β-carotene bleaching, ferric reducing, and hydroxyl radical scavenging activities. Results of DPPH assay showed no significant difference ( p < 0.001) between EESAL and butylated hydroxyanisole [BHA], while EESAL exhibited a significantly ( p < 0.001) higher activity than BHT [butylated hydroxytoluene]. Phosphomolybdate method recorded a total antioxidant capacity of 190.00 ± 70.53 µg butylated hydroxytoluene equivalents [BHTE]/mg dry extract, while β-carotene bleaching assay gave percent antioxidant activities of both EESAL and BHT as 81.46±1.62 and 80.90±1.39 respectively. Ferric reducing abilities of both EESAL and ascorbic acid increased in a concentration-dependent manner with EESAL displaying a significantly ( p < 0.001) higher reductive activity than vitamin C. EESAL displayed a significantly higher hydroxyl radical scavenging activity as compared with BHT at the lowest concentration with no significant difference at the highest concentration. Total phenolic and flavonoid contents of EESAL were obtained as 608.10 ± 2.12 µg GAE/mg and 78.96 ± 3.37 µg QE/mg respectively. Taken together, the free radical scavenging and antioxidant activity of EESAL is likely due to its high phenolic content with complementary effects of the flavonoid components.

Comparative Evaluation of Polyphenol Contents and Antioxidant Activities between Ethanol Extracts of Vitex negundo and Vitex trifolia L. Leaves by Different Methods.

PubMed

Saklani, Sarla; Mishra, Abhay Prakash; Chandra, Harish; Atanassova, Maria Stefanova; Stankovic, Milan; Sati, Bhawana; Shariati, Mohammad Ali; Nigam, Manisha; Khan, Mohammad Usman; Plygun, Sergey; Elmsellem, Hicham; Suleria, Hafiz Ansar Rasul

2017-09-27

The in vitro antioxidant potential assay between ethanolic extracts of two species from the genus Vitex ( Vitex negundo L. and Vitex trifolia L.) belonging to the Lamiaceae family were evaluated. The antioxidant properties of different extracts prepared from both plant species were evaluated by different methods. DPPH scavenging, nitric oxide scavenging, and β-carotene-linoleic acid and ferrous ion chelation methods were applied. The antioxidant activities of these two species were compared to standard antioxidants such as butylated hydroxytoluene (BHT), ascorbic acid, and Ethylene diamine tetra acetic acid (EDTA). Both species of Vitex showed significant antioxidant activity in all of the tested methods. As compared to V. trifolia L. (60.87-89.99%; 40.0-226.7 μg/mL), V. negundo has been found to hold higher antioxidant activity (62.6-94.22%; IC 50 = 23.5-208.3 μg/mL) in all assays. In accordance with antioxidant activity, total polyphenol contents in V. negundo possessed greater phenolic (89.71 mg GAE/g dry weight of extract) and flavonoid content (63.11 mg QE/g dry weight of extract) as compared to that of V. trifolia (77.20 mg GAE/g and 57.41 mg QE/g dry weight of extract respectively). Our study revealed the significant correlation between the antioxidant activity and total phenolic and flavonoid contents of both plant species.

Health-Promoting Effects of Thymus herba-barona, Thymus pseudolanuginosus, and Thymus caespititius Decoctions

PubMed Central

Afonso, Andrea F.; Pereira, Olívia R.; Neto, Rodrigo T.

2017-01-01

Thymus herba-barona, Thymus pseudolanuginosus, and Thymus caespititius decoctions were screened for their phenolic constituents, along with their potential antioxidant, anti-inflammatory, and antibacterial activities. The total phenolic compounds in the extracts of the three plants ranged from 236.0 ± 26.6 mgGAE/g (T. caespititus) to 293.0 ± 30.5 mgGAE/g of extract (T. pseudolanuginosus), being particularly rich in caffeic acid derivatives, namely rosmarinic acid and its structural isomers, as well as flavones, such as luteolin-O-glucuronide. The T. pseudolanuginosus extract presented the best DPPH radical scavenging ability (EC50 = 10.9 ± 0.7 µg/mL), a high reducing power (EC50 = 32.2 ± 8.2 µg/mL), and effectively inhibited the oxidation of β-carotene (EC50 = 2.4 ± 0.2 µg/mL). The extracts also showed NO● scavenging activity close to that of ascorbic acid, and thus might be useful as anti-inflammatory agents. In addition, they exhibited antibacterial activity against gram-negative and gram-positive bacteria. Staphylococcus aureus strains were the most sensitive bacteria to thyme extracts, with minimum inhibitory concentration and minimum bactericidal concentration values in the range of 0.6–3.5 mg/mL. Overall, this work is an important contribution for the phytochemical characterization and the potential antioxidant, anti-inflammatory, and antimicrobial activities of these three Thymus species, which have been poorly explored. PMID:28858228

Effects of ascorbate on leucocytes: Part II. Effects of ascorbic acid and calcium and sodium ascorbate on neutrophil phagocytosis and post-phagocytic metabolic activity.

PubMed

Anderson, R

1979-09-01

The effects of ascorbic acid and calcium and sodium ascorbate at a concentration range of 10(-6)M - 10(-1)M on polymorphonuclear leucocyte (PMN) phagocytosis of Candida albicans and post-phagocytic nitroblue tetrazolium (NBT) reduction, hexose monophosphate shunt (HMS) activity and myeloperoxidase-mediated iodination of ingested protein were investigated. Phagocytosis of C. albicans was unaffected by ascorbate concentrations of 10(-6)M - 10(-2)M; however, progressive inhibition was observed at concentrations of 10(-2)M upwards. Enhancement of resting and stimulated HMS activity and NBT reduction was evident at ascorbate concentrations of 10(-5) M - 10(-2)M. The stimulations of HMS activity and NBT reduction was independent of myeloperoxidase iodination of ingested protein and this latter function was strongly inhibited by ascorbate. Concentrations of ascorbic acid and calcium and sodium ascorbate which caused inhibition of phagocytosis and HMS activity were the same as those which mediated stimulation of cell motility, indicating that independent cellular mechanisms may govern motility and phagocytosis.

Further Studies on Oxalic Acid Biosynthesis in Oxalate-accumulating Plants 1

PubMed Central

Nuss, Richard F.; Loewus, Frank A.

1978-01-01

l-Ascorbic acid functions as a precursor of oxalic acid in several oxalate-accumulating plants. The present study extends this observation to include Rumex crispus L. (curly dock), Amaranthus retroflexus L. (red root pigweed), Chenopodium album L. (lamb's-quarters), Beta vulgaris L. (sugar beet), Halogeton glomeratus M. Bieb. (halogeton), and Rheum rhabarbarum L. (rhubarb). Several species with low oxalate content are also examined. When l-[1-14C]ascorbic acid is supplied to young seedlings of R. crispus or H. glomeratus, a major portion of the 14C is released over a 24-hour period as 14CO2 and only a small portion is recovered as [14C]oxalate, unlike cuttings from 2- or 4-month-old plants which retain a large part of the 14C as [14C]oxalic acid and release very little 14CO2. Support for an intermediate role of oxalate in the release of 14CO2 from l-[1-14C]ascorbic acid is seen in the rapid release of 14CO2 by R. crispus and H. glomeratus seedlings labeled with [14C]oxalic acid. The common origin of oxalic acid carbon in the C1 and C2 fragment from l-ascorbic acid is demonstrated by comparison of 14C content of oxalic acid in several oxalate-accumulators after cuttings or seedlings are supplied equal amounts of l-[1-14C]- or l-[UL-14C]ascorbic acid. Theoretically, l-[1-14C]ascorbic acid will produce labeled oxalic acid containing three times as much 14C as l-[UL-14C]ascorbic acid when equal amounts of label are provided. Experimentally, a ratio of 2.7 ± 0.5 is obtained in duplicate experiments with six different species. PMID:16660342

Structure, spectra and antioxidant action of ascorbic acid studied by density functional theory, Raman spectroscopic and nuclear magnetic resonance techniques.

PubMed

Singh, Gurpreet; Mohanty, B P; Saini, G S S

2016-02-15

Structure, vibrational and nuclear magnetic resonance spectra, and antioxidant action of ascorbic acid towards hydroxyl radicals have been studied computationally and in vitro by ultraviolet-visible, nuclear magnetic resonance and vibrational spectroscopic techniques. Time dependant density functional theory calculations have been employed to specify various electronic transitions in ultraviolet-visible spectra. Observed chemical shifts and vibrational bands in nuclear magnetic resonance and vibrational spectra, respectively have been assigned with the help of calculations. Changes in the structure of ascorbic acid in aqueous phase have been examined computationally and experimentally by recording Raman spectra in aqueous medium. Theoretical calculations of the interaction between ascorbic acid molecule and hydroxyl radical predicted the formation of dehydroascorbic acid as first product, which has been confirmed by comparing its simulated spectra with the corresponding spectra of ascorbic acid in presence of hydrogen peroxide. Copyright © 2015 Elsevier B.V. All rights reserved.

Decalcification by ascorbic acid for immuno- and affinohistochemical techniques on the inner ear.

PubMed

Merchán-Pérez, A; Gil-Loyzaga, P; Bartolomé, M V; Remezal, M; Fernández, P; Rodríguez, T

1999-08-01

An ascorbic acid decalcifying solution was applied to immuno- and affinohistochemical studies on the inner ear. Rat inner ears fixed in 4% paraformaldehyde in PBS or in 2% acetic acid in ethanol solutions were adequately decalcified in an ascorbic acid solution, at a temperature of 4 degrees C. The decalcifying solution was prepared with 1% ascorbic acid and 0.84% sodium chloride in distilled water (pH 2.5-2.6). The decalcification time was in a direct relationship to the specimen calcification. In this study, two neuroactive substances (gamma-aminobutyric acid and calcitonin gene-related peptide), neurofilaments, and the galectine endogenous lectin were successfully detected immunohistochemically.

A Bioengineered Human Skin Equivalent (HSE) for the Evaluation of Protectants

DTIC Science & Technology

2006-11-01

agonist clofibrate to the growth media. Medium supplemented with 25 μM palmitic acid , 15 μM linoleic acid , 25 μM oleic acid , 7 μM arachidonic acid , 0.25...granules (indicated by arrows). Fig. 6: A cross section of the HSE with lipids, ascorbic acid and clofibrate supplementation. The combination of... Clofibrate , Ascorbic Acid and Lipids Compared With the Lipid Profile of Native Human Skin. Clofibrate 300 μM Lipid class Control No ascorbic

Plasma concentrations of ascorbic acid and C-reactive protein, and risk of future coronary artery disease, in apparently healthy men and women: the EPIC-Norfolk prospective population study.

PubMed

Boekholdt, S Matthijs; Meuwese, Marijn C; Day, Nicholas E; Luben, Robert; Welch, Ailsa; Wareham, Nicholas J; Khaw, Kay-Tee

2006-09-01

High plasma concentrations of ascorbic acid, a marker of fruit and vegetable intake, are associated with low risk of coronary artery disease. Whether this relationship is explained by a reduction in systemic inflammation is unclear. We investigated the relationship between ascorbic acid plasma concentration and coronary artery disease risk, and in addition whether this relationship depended on classical risk factors and C-reactive protein (CRP) concentration. We used a prospective nested case-control design. The study consisted of 979 cases and 1794 controls (1767 men and 1006 women). Increasing ascorbic acid quartiles were associated with lower age, BMI, systolic and diastolic blood pressure, and CRP concentration, but with higher HDL-cholesterol concentration. No associations existed between ascorbic acid concentration and total cholesterol concentration or LDL-cholesterol concentration. When data from men and women were pooled, the risk estimates decreased with increasing ascorbic acid quartiles such that people in the highest ascorbic acid quartile had an odds ratio for future coronary artery disease of 0.67 (95 % CI 0.52, 0.87) compared with those in the lowest quartile (P for linearity=0.001). This relationship was independent of sex, age, diabetes, smoking, BMI, LDL-cholesterol, HDL-cholesterol, systolic blood pressure and CRP level. These data suggest that the risk reduction associated with higher ascorbic acid plasma concentrations, a marker of fruit and vegetable intake, is independent of classical risk factors and also independent of CRP concentration.

Determination of some selected secondary metabolites and their invitro antioxidant activity in commercially available Ethiopian tea (Camellia sinensis).

PubMed

Bizuayehu, Dereje; Atlabachew, Minaleshewa; Ali, Mirtachew Tihar

2016-01-01

Eight brands of tea (Camellia sinensis),which are cultivated and commercially available in Ethiopian market, were analyzed for estimation of their total secondary metabolites (polyphenols, flavonoids and tannins) content and free radical scavenging activity which is expressed on dry weight basis. In this present study, the total polyphenols, tannin and flavonoid contents were studied spectrophotometrically using Folin-Dennis, Folin-Dennis/protein precipitation and aluminium chloride methods respectively. The free radical scavenging activity was determined by using DPPH radical assay. Results of the analysis revealed that the total polyphenol content varied from 21.3 ± 0.24 to 31.6 ± 0.31 mg of gallic acid equivalent/g of dry matter. Total flavonoids content in the tea samples varied from 8.17 ± 0.68 to 23.2 ± 0.68 mg of catechin equivalent/g of dry weight and tannin content varied from 5.64 ± 0.39 7.45 ± 0.27 mg tannic acid equivalent/g of dry weight basis. The free radical scavenging activity among the tea brand samples ranged from 28.8 ± 1.86 to 80.0 ± 0.63 mg ascorbic acid equivalent/g and the half maximal inhibitory concentration (IC50%) values varied from 7.3 ± 1.35 to 64.0 ± 2.81 µg/mL of extract. The correlation between the antioxidant activity with total polyphenol content (R = 0.91325), with flavonoids (R = 0.80658) and with tannin (R = 0.73125) was calculated and maximum correlation value was found between polyphenol content and the free radical scavenging activity of the tea samples. The results in this study also revealed that green tea had the higher polyphenolic content and found to have the most promising antioxidant activity. This study further confirmed that Ethiopia tea is reach in phenolic compounds as compared to some overseas tea cultivars/varieties.

Variation in the SLC23A1 gene does not influence cardiometabolic outcomes to the extent expected given its association with l-ascorbic acid1234

PubMed Central

Wade, Kaitlin H; Forouhi, Nita G; Cook, Derek G; Johnson, Paul; McConnachie, Alex; Morris, Richard W; Rodriguez, Santiago; Ye, Zheng; Ebrahim, Shah; Padmanabhan, Sandosh; Watt, Graham; Bruckdorfer, K Richard; Wareham, Nick J; Whincup, Peter H; Chanock, Stephen; Sattar, Naveed; Lawlor, Debbie A; Davey Smith, George; Timpson, Nicholas J

2015-01-01

Background: Observational studies showed that circulating l-ascorbic acid (vitamin C) is inversely associated with cardiometabolic traits. However, these studies were susceptible to confounding and reverse causation. Objectives: We assessed the relation between l-ascorbic acid and 10 cardiometabolic traits by using a single nucleotide polymorphism in the solute carrier family 23 member 1 (SLC23A1) gene (rs33972313) associated with circulating l-ascorbic acid concentrations. The observed association between rs33972313 and cardiometabolic outcomes was compared with that expected given the rs33972313-l-ascorbic acid and l-ascorbic acid–outcome associations. Design: A meta-analysis was performed in the following 5 independent studies: the British Women's Heart and Health Study (n = 1833), the MIDSPAN study (n = 1138), the Ten Towns study (n = 1324), the British Regional Heart Study (n = 2521), and the European Prospective Investigation into Cancer (n = 3737). Results: With the use of a meta-analysis of observational estimates, inverse associations were shown between l-ascorbic acid and systolic blood pressure, triglycerides, and the waist-hip ratio [the strongest of which was the waist-hip ratio (−0.13-SD change; 95% CI: −0.20-, −0.07-SD change; P = 0.0001) per SD increase in l-ascorbic acid], and a positive association was shown with high-density lipoprotein (HDL) cholesterol. The variation at rs33972313 was associated with a 0.18-SD (95% CI: 0.10-, 0.25-SD; P = 3.34 × 10−6) increase in l-ascorbic acid per effect allele. There was no evidence of a relation between the variation at rs33972313 and any cardiometabolic outcome. Although observed estimates were not statistically different from expected associations between rs33972313 and cardiometabolic outcomes, estimates for low-density lipoprotein cholesterol, HDL cholesterol, triglycerides, glucose, and body mass index were in the opposite direction to those expected. Conclusions: The nature of the genetic association exploited in this study led to limited statistical application, but despite this, when all cardiometabolic traits were assessed, there was no evidence of any trend supporting a protective role of l-ascorbic acid. In the context of existing work, these results add to the suggestion that observational relations between l-ascorbic acid and cardiometabolic health may be attributable to confounding and reverse causation. PMID:25527764

Effect of Docosahexaenoic Acid Ingestion on Temporal Change in Urinary Excretion of Mercapturic Acid in ODS Rats.

PubMed

Sekine, Seiji; Kubo, Kazuhiro; Tadokoro, Tadahiro; Saito, Morio

2007-11-01

We hypothesized a suppressive mechanism for docosahexaenoic acid (22:6n-3; DHA)-induced tissue lipid peroxidation in which the degradation products, especially aldehydic compounds, are conjugated with glutathione through catalysis by glutathione S-transferases, and then excreted into urine as mercapturic acids. In the present study, ascorbic acid-requiring ODS rats were fed a diet containing DHA (3.6% of total energy) for 31 days. Lipid peroxides including degradation products and their scavengers in the liver and kidney were determined, and the temporal change in the urinary excretion of mercapturic acids was also measured. The activity of aldehyde dehydrogenase, which catalyzes the oxidation and detoxification of aldehydes, tended to be higher in the liver of DHA-fed rats. The levels of lipid peroxides as measured by thiobarbituric acid-reactive substances and aldehydic compounds were higher and that of alpha-tocopherol was lower in the liver, and the pattern of temporal changes in the urinary excretion of mercapturic acids was also different between the n-6 linoleic acid and DHA-fed rats. Accordingly, we presume from these results that after dietary DHA-induced lipid peroxidation, a proportion of the lipid peroxidation-derived aldehydic degradation products is excreted into urine as mercapturic acids.

Effect of Docosahexaenoic Acid Ingestion on Temporal Change in Urinary Excretion of Mercapturic Acid in ODS Rats

PubMed Central

Sekine, Seiji; Kubo, Kazuhiro; Tadokoro, Tadahiro; Saito, Morio

2007-01-01

We hypothesized a suppressive mechanism for docosahexaenoic acid (22:6n-3; DHA)-induced tissue lipid peroxidation in which the degradation products, especially aldehydic compounds, are conjugated with glutathione through catalysis by glutathione S-transferases, and then excreted into urine as mercapturic acids. In the present study, ascorbic acid-requiring ODS rats were fed a diet containing DHA (3.6% of total energy) for 31 days. Lipid peroxides including degradation products and their scavengers in the liver and kidney were determined, and the temporal change in the urinary excretion of mercapturic acids was also measured. The activity of aldehyde dehydrogenase, which catalyzes the oxidation and detoxification of aldehydes, tended to be higher in the liver of DHA-fed rats. The levels of lipid peroxides as measured by thiobarbituric acid-reactive substances and aldehydic compounds were higher and that of α-tocopherol was lower in the liver, and the pattern of temporal changes in the urinary excretion of mercapturic acids was also different between the n-6 linoleic acid and DHA-fed rats. Accordingly, we presume from these results that after dietary DHA-induced lipid peroxidation, a proportion of the lipid peroxidation-derived aldehydic degradation products is excreted into urine as mercapturic acids. PMID:18299714

Effect of ascorbic acid on prevention of hypercholesterolemia induced atherosclerosis.

PubMed

Das, S; Ray, R; Snehlata; Das, N; Srivastava, L M

2006-04-01

The notion that oxidation of lipids and propagation of free radicals may contribute to the pathogenesis of atherosclerosis is supported by a large body of evidence. To circumvent the damage caused by oxygen free radicals, antioxidants are needed which provide the much needed neutralization of free radical by allowing the pairing of electrons. In this study we have investigated the effect of ascorbic acid, a water soluble antioxidant on the development of hypercholesterolemia induced atherosclerosis in rabbits. Rabbits were made hypercholesterolemic and atherosclerotic by feeding 100 mg cholesterol/day. Different doses of ascorbic acid were administered to these rabbits. Low dose of ascorbic acid (0.5 mg/100 g body weight/day) did not have any significant effect on the percent of total area covered by atherosclerotic plaque. However, ascorbic acid when fed at a higher dose (15 mg/100 g body weight/day) was highly effective in reducing the atherogenecity. With this dose the percent of total surface area covered by atherosclerotic plaque was significantly less (p < 0.001). This suggests that use of ascorbic acid may have great promise in the prevention of hypercholesterolemia induced atherosclerosis.

Adding of ascorbic acid to the culture medium influences the antioxidant status and some biochemical parameters in the hen granulosa cells.

PubMed

Capcarova, M; Kolesarova, A; Kalafova, A; Bulla, J; Sirotkin, A V

2015-07-01

The aim of the present study was to determine the activity of superoxide dismutase (SOD), total antioxidant status (TAS) of the hen granulosa cells, and selected biochemical parameters, including calcium, phosphorus, sodium, potassium, glucose, cholesterol, proteins, in the culture medium of granulosa cells after exposing them to ascorbic acid in vitro conditions. Ovarian granulosa cells of hens were incubated with various doses of ascorbic acid (E1 0.09 mg/ml, E2 0.13 mg/ml, E3 0.17 mg/ml, E4 0.33 mg/ml, E5 0.5 mg/ml). Ascorbic acid did not manifest antioxidant potential and higher doses of ascorbic acid (0.17; 0.33 and 0.5 mg/ml) decreased the activity of SOD in granulosa cells. Vitamin application resulted in a significantly (p<0.05) higher accumulation of Na+ and K+ in culture media of granulosa cells and decreased the concentration of glucose and proteins. These results indicate that ascorbic acid might be involved in the regulation of selected biochemical and physiological processes in ovarian granulosa cells.

Effect of L-ascorbic acid on nickel-induced alterations in serum lipid profiles and liver histopathology in rats.

PubMed

Das, Kusal K; Gupta, Amrita Das; Dhundasi, Salim A; Patil, Ashok M; Das, Swastika N; Ambekar, Jeevan G

2006-01-01

Nickel exposure greatly depletes intracellular ascorbate and alters ascorbate-cholesterol metabolism. We studied the effect of the simultaneous oral treatment with L-ascorbic acid (50 mg/100 g body weight (BW) and nickel sulfate (2.0 mg/100 g BW, i.p) on nickelinduced changes in serum lipid profiles and liver histopathology. Nickel-treated rats showed a significant increase in serum low-density lipoprotein-cholesterol, total cholesterol, triglycerides, and a significant decrease in serum high-density lipoprotein-cholesterol. In the liver, nickel sulfate caused a loss of normal architecture, fatty changes, extensive vacuolization in hepatocytes, eccentric nuclei, and Kupffer cell hypertrophy. Simultaneous administration of L-ascorbic acid with nickel sulfate improved both the lipid profile and liver impairments when compared with rats receiving nickel sulfate only. The results indicate that L-ascorbic acid is beneficial in preventing nickel-induced lipid alterations and hepatocellular damage.

Influence of ascorbic acid on iron absorption from an iron-fortified, chocolate-flavored milk drink in Jamaican children.

PubMed

Davidsson, L; Walczyk, T; Morris, A; Hurrell, R F

1998-05-01

The influence of ascorbic acid on iron absorption from an iron-fortified, chocolate-flavored milk drink (6.3 mg total Fe per serving) was evaluated with a stable-isotope technique in 20 6-7-y-old Jamaican children. Each child received two test meals labeled with 5.6 mg 57Fe and 3.0 mg 58Fe as ferrous sulfate on 2 consecutive days. Three different doses of ascorbic acid (0, 25, and 50 mg per 25-g serving) were evaluated in two separate studies by using a crossover design. Iron isotope ratios were measured by negative thermal ionization mass spectrometry. In the first study, iron absorption was significantly greater (P < 0.0001) after the addition of 25 mg ascorbic acid: geometric mean iron absorption was 1.6% (range: 0.9-4.2%) and 5.1% (2.2-17.3%) for the test meals containing 0 and 25 mg ascorbic acid, respectively. In the second study, a significant difference (P < 0.05) in iron absorption was observed when the ascorbic acid content was increased from 25 to 50 mg: geometric mean iron absorption was 5.4% (range: 2.7-10.8%) compared with 7.7% (range: 4.7-16.5%), respectively. The chocolate drink contained relatively high amounts of polyphenolic compounds, phytic acid, and calcium, all well-known inhibitors of iron absorption. The low iron absorption without added ascorbic acid shows that chocolate milk is a poor vehicle for iron fortification unless sufficient amounts of an iron-absorption enhancer are added. Regular consumption of iron-fortified chocolate milk drinks containing added ascorbic acid could have a positive effect on iron nutrition in population groups vulnerable to iron deficiency.

GST ( phi) gene from Macrophyte Lemna minor is involved in cadmium exposure responses

NASA Astrophysics Data System (ADS)

Chen, Shihua; Chen, Xin; Dou, Weihong; Wang, Liang; Yin, Haibo; Guo, Shanli

2016-03-01

Reactive oxygen species (ROS) scavengers, including ascorbate peroxidase, superoxide dismutase, catalase and peroxidase, are the most commonly used biomarkers in assessing an organisms' response to many biotic and abiotic stresses. In this study, we cloned an 866 bp GST ( phi) gene in Lemna minor and investigated its characteristics, expression and enzymatic activities under 75 μmol/L cadmium concentrations in comparison with other ROS scavengers. GST ( phi) gene expression patterns were similar to those of other scavengers of ROS. This suggests that GST ( phi) might be involved in responding to heavy metal (cadmium) stress and that its expression level could be used as a bio-indicator in monitoring cadmium pollution.

Chemical composition and organoleptic evaluation of juice from steamed cashew apple blended with orange juice.

PubMed

Inyang, U E; Abah, U J

1997-01-01

Fully riped cashew apples (yellow variety) were steamed for 7 minutes prior to juice extraction. The extracted juice was blended with various proportions of sweet orange juice. Chemical composition and organoleptic evaluation were carried out on both the blended and unblended juices. The ascorbic acid content of unsteamed cashew apple juice was 287 mg/100 ml. Steaming of the cashew apple prior to juice extraction resulted in a decreased (230 mg/100 ml) content of ascorbic acid. It also led to slight decreases in soluble solids and titratable acidity. A comparison of the chemical composition of the two juices showed that the orange juice contained more sugars, titratable acidity and soluble solids but less ascorbic acid than cashew apple juice. Consequently, the soluble solids, titratable acidity, reducing and total sugars of the blends increased with increase in the proportions of orange juice while the content of ascorbic acid was decreasing. In spite of the decrease in ascorbic acid content of the blends, results showed that blended juice would no doubt be a very good source of ascorbic acid. Result of the organoleptic evaluation revealed that a 60% cashew apple and 40% orange juice gave a good quality juice in terms of flavor, after taste and overall acceptability.

In vitro and in vivo antioxidant activities of the aqueous extract of Celosia argentea leaves

PubMed Central

Malomo, S. O.; Ore, A.; Yakubu, M. T.

2011-01-01

Objective: The aqueous extract of Celosia argentea var. cristata L. leaves at 100, 200, and 400 mg/kg body weight (b.w.) was investigated against cadmium (Cd)-induced oxidative stress in Wistar rats. The in vitro antioxidant of the extract was evaluated using ammonium thiocyanate, reducing power, and membrane stabilizing models. Materials and Methods: For the in vivo study, 30 male rats (Rattus norvegicus) weighing 138.02 ± 7.02 g were completely randomized into 6 groups (A–F) of 5 animals each. Animals in groups A and B received 0.5 ml of distilled water and the same volume containing 8 mg/kg b.w. of Cd, respectively, for 7 days orally. Animals in groups C, D, E, and F were treated like those in group B except that they received 100 mg/kg b.w. of ascorbic acid, and 100, 200, and 400 mg/kg b.w. of the extract, respectively, in addition to Cd. Results: Phytochemical screening revealed the presence of alkaloids (0.61%), saponins (2.93%), cardiac glycosides (0.21%), cardenolides (0.20%), phenolics (3.26%), and flavonoids (2.38%). A total of 10 mg/ml of the extract inhibited linoleic acid oxidation by 67.57%. The highest reducing power was 100 mg/ml as against 10 mg/ml for ascorbic acid. In addition, 2 mg/ml of the extract produced a membrane stabilizing activity of 63.49% as against 77.46% for indomethacin. Compared with the distilled water control group, the administration of Cd alone significantly (P < 0.05) decreased the alkaline phosphatase activity of the rat liver and brain. This decrease was accompanied by a corresponding increase in the serum enzyme. The simultaneous administration of the extract and Cd produced an enzyme activity that compared favorably (P > 0.05) with the animals that received Cd and ascorbic acid. In addition, the reduction in the superoxide dismutase and catalase activity of the liver and brain of the animals, serum uric acid, albumin and bilirubin, and also the increase in the serum malondialdehyde content in animals treated with Cd alone was attenuated by the extract; the values compared well (P > 0.05) with those simultaneously administered with Cd and ascorbic acid. Conclusion: Overall, the results indicated that the aqueous extract of C. argentea leaves attenuated Cd-induced oxidative stress in the animals, with the best result at 400 mg/kg b.w. The antioxidant activity of the extract may be attributed to the phenolic and flavonoid components of the extract. The induction of antioxidant enzymes and scavenging of free radicals may account for the mechanism of action of the extract as an antioxidant. PMID:21713091

Rectal gel application of Withania somnifera root extract expounds anti-inflammatory and muco-restorative activity in TNBS-induced Inflammatory Bowel Disease

PubMed Central

2011-01-01

Background Inflammatory Bowel Disease (IBD) is marked with chronic inflammation of intestinal epithelium driven by oxidative stress. Traditional treatments with plant extracts gained renewed interest due to their ability to ameliorate the multi factorial conditions like inflammation. We investigated the beneficial effects of Withania somnifera in Trinitro Benzyl Sulfonic Acid (TNBS) induced experimental IBD through a rectally applicable formulation. Methods The study included (i) preparation of gel formulation from aqueous Withania somnifera root extract (WSRE), (ii) biochemical assays to determine its performance potential, (iii) testing of formulation efficacy in TNBS-induced IBD rat model, and (iv) histo-patholgical studies to assess its healing and muco-regenerative effect in IBD-induced rats. For this purpose, concentration dependant antioxidant activity of the extracts were evaluated using biochemical assays like (a) inhibition of lipid peroxidation, (b) NO scavenging, (c) H2O2 scavenging, and (d) ferric reducing power assay. Results The extract, at 500 μg/ml, the highest concentration tested, showed 95.6% inhibition of lipid peroxidation, 14.8% NO scavenging, 81.79% H2O2 scavenging and a reducing capacity of 0.80. The results were comparable with standard antioxidants, ascorbic acid and curcumin. WSRE treatment positively scored on histopathological parameters like necrosis, edema, neutrophil infiltration. The post treatment intestinal features showed restoration at par with the healthy intestine. In view of these results, gel formulation containing an aqueous extract of W. somnifera, prepared for rectal application was tested for its anti-inflammatory activity in TNBS-induced rat models for IBD. Commercially available anti-inflammatory drug Mesalamine was used as the standard in this assay. Conclusions Dose of the rectal gel applied at 1000 mg of WSRE per kg rat weight showed significant muco-restorative efficacy in the IBD-induced rats, validated by histo-pathological studies. PMID:21527003

Further investigations on the role of ascorbic acid in stratum corneum lipid models after UV exposure.

PubMed

Trommer, Hagen; Böttcher, Rolf; Huschka, Christoph; Wohlrab, Wolfgang; Neubert, Reinhard H H

2005-08-01

This study is the continuation of our research into vitamin C and its possible effects on human skin after topical administration. The effects of ascorbic acid, iron ions and UV irradiation on stratum corneum lipid models were investigated. The lipid models used were: a simple system (linolenic acid dispersion), a complex system (liposomes consisting of dipalmitoylphosphatidylcholine, cholesterol and linolenic acid) and complex systems with additionally incorporated ceramides (types III and IV). The lipid peroxidation was quantified by the thiobarbituric acid assay. A human adult low-calcium high-temperature (HaCaT) keratinocytes cell culture was used as a second in-vitro model. The amount of intracellular peroxides was determined by measuring the fluorescence intensity using the dihydrorhodamine 123 assay. Electron paramagnetic resonance spectroscopy was used to study the influence of ascorbic acid and iron ions on the signal intensity of 5-doxylstearic acid during UV exposure. Ascorbic acid showed prooxidative properties in the thiobarbituric acid assay whereas cell protection was measured in the HaCaT keratinocytes experiments. Electron paramagnetic resonance investigations revealed different extents of free radical production generated by iron ions, ascorbic acid and UV irradiation. In evaluating the results from this study new aspects of the mechanism of lipid damage caused by these three factors were suggested, transcending the simple redox behaviour of ascorbic acid.

Stability and anti-glycation properties of intermediate moisture apple products fortified with green tea.

PubMed

Lavelli, Vera; Corey, Mark; Kerr, William; Vantaggi, Claudia

2011-07-15

Intermediate moisture products made from blanched apple flesh and green tea extract (about 6mg of monomeric flavan 3-ols added per g of dry apple) or blanched apple flesh (control) were produced, and their quality attributes were investigated over storage for two months at water activity (a(w)) levels of 0.55 and 0.75, at 30°C. Products were evaluated for colour (L(∗), a(∗), and b(∗) Hunter's parameters), phytochemical contents (flavan 3-ols, chlorogenic acid, dihydrochalcones, ascorbic acid and total polyphenols), ferric reducing antioxidant potential, 2,2-diphenyl-1-(2,4,6-trinitrophenyl)hydrazyl radical-scavenging activity and ability to inhibit formation of fructose-induced advanced glycation end-products. During storage of the fortified and unfortified intermediate moisture apples, water availability was sufficient to support various chemical reactions involving phytochemicals, which degraded at different rates: ascorbic acid>flavan 3-ols>dihydrochalcones and chlorogenic acid. Colour variations occurred at slightly slower rates after green tea addition. In the intermediate moisture apple, antioxidant and anti-glycoxidative properties decreased at similar rates (half-life was about 80d at a(w) of 0.75, 30°C). In the green tea-fortified intermediate moisture apple, the antioxidant activity decreased at a slow rate (half-life was 165d at a(w) of 0.75, 30°C) and the anti-glycoxidative properties did not change, indicating that flavan 3-ol degradation involved the formation of derivatives that retained the properties of their parent compounds. Since these properties are linked to oxidative- and advanced glycation end-product-related diseases, these results suggest that green tea fortification of intermediate moisture apple products could be a valuable means of product innovation, to address consumers' nutritional needs. Copyright © 2011 Elsevier Ltd. All rights reserved.

Electronic structures and spectra of two antioxidants: uric acid and ascorbic acid

NASA Astrophysics Data System (ADS)

Shukla, M. K.; Mishra, P. C.

1996-04-01

Electronic absorption and fluorescence spectra of aqueous solutions of two well known antioxidants, uric acid and ascorbic acid (vitamin C), have been studied at different pH. The observed spectra have been interpreted in terms of neutral and anionic forms of the molecules with the help of molecular orbital calculations. The N 3 site of uric acid has been shown to be the most acidic. Fluorescence of uric acid seems to originate from an anion of the molecule in a wide pH range. Around pH 3, both the neutral and anionic forms of ascorbic acid appear to be present in aqueous solutions. In aqueous media, ascorbic acid appears to get converted easily to its dehydro form and this conversion does not seem to be reversible. An anion of dehydroascorbic acid seems to be formed on heating dehydroascorbic acid in aqueous solutions.

Oxidative DNA damage preventive activity and antioxidant potential of plants used in Unani system of medicine

PubMed Central

2010-01-01

Background There is increasing recognition that many of today's diseases are due to the "oxidative stress" that results from an imbalance between the formation and neutralization of reactive molecules such as reactive oxygen species (ROS) and reactive nitrogen species (RNS), which can be removed with antioxidants. The main objective of the present study was to evaluate the antioxidant activity of plants routinely used in the Unani system of medicine. Several plants were screened for radical scavenging activity, and the ten that showed promising results were selected for further evaluation. Methods Methanol (50%) extracts were prepared from ten Unani plants, namely Cleome icosandra, Rosa damascena, Cyperus scariosus, Gardenia gummifera, Abies pindrow, Valeriana wallichii, Holarrhena antidysenterica, Anacyclus pyrethrum, Asphodelus tenuifolius and Cyperus scariosus, and were used to determine their total phenolic, flavonoid and ascorbic acid contents, in vitro scavenging of DPPH·, ABTS·+, NO, ·OH, O2.- and ONOO-, and capacity to prevent oxidative DNA damage. Cytotoxic activity was also determined against the U937 cell line. Results IC50 values for scavenging DPPH·, ABTS·+, NO, ·OH, O2.- and ONOO- were in the ranges 0.007 ± 0.0001 - 2.006 ± 0.002 mg/ml, 2.54 ± 0.04 - 156.94 ± 5.28 μg/ml, 152.23 ± 3.51 - 286.59 ± 3.89 μg/ml, 18.23 ± 0.03 - 50.13 ± 0.04 μg/ml, 28.85 ± 0.23 - 537.87 ± 93 μg/ml and 0.532 ± 0.015 - 3.39 ± 0.032 mg/ml, respectively. The total phenolic, flavonoid and ascorbic acid contents were in the ranges 62.89 ± 0.43 - 166.13 ± 0.56 mg gallic acid equivalent (GAE)/g extract, 38.89 ± 0.52 - 172.23 ± 0.08 mg quercetin equivalent (QEE)/g extract and 0.14 ± 0.09 - 0.98 ± 0.21 mg AA/g extract. The activities of the different plant extracts against oxidative DNA damage were in the range 0.13-1.60 μg/ml. Of the ten selected plant extracts studied here, seven - C. icosandra, R. damascena, C. scariosus, G. gummifera, A. pindrow, V. wallichii and H. antidysenterica - showed moderate antioxidant activity. Finally, potentially significant oxidative DNA damage preventive activity and antioxidant activity were noted in three plant extracts: C. icosandra, R. damascena and C. scariosus. These three plant extracts showed no cytotoxic activity against U937 cells. Conclusions The 50% methanolic extracts obtained from different plant parts contained significant amounts of polyphenols with superior antioxidant activity as evidenced by the scavenging of DPPH·, ABTS·+, NO, ·OH, O2.- and ONOO-. C. icosandra, R. damascena and C. scariosus showed significant potential for preventing oxidative DNA damage and radical scavenging activity, and the G. gummifera, A. pindrow, V. wallichii, H. antidysenterica, A. pyrethrum, A. tenuifolius and O. mascula extracts showed moderate activity. The extracts of C. icosandra, R. damascena and C. scariosus showed no cytotoxicity against U937 cells. In conclusion, these routinely used Unani plants, especially C. icosandra, R. damascena and C. scariosus, which are reported to have significant activity against several human ailments, could be exploited as potential sources of natural antioxidants for plant-based pharmaceutical industries. PMID:21159207

Vitamin C transporter gene polymorphisms, dietary vitamin C and serum ascorbic acid.

PubMed

Cahill, Leah E; El-Sohemy, Ahmed

2009-01-01

Vitamin C transporter proteins SVCT1 and SVCT2 are required for the absorption and transport of vitamin C in humans. This study aims to determine whether common SVCT genotypes modify the association between dietary vitamin C and serum ascorbic acid. Non-smoking men and women (n=1,046) aged 20-29 were participants of the Toronto Nutrigenomics and Health Study. Overnight fasting blood samples were collected to determine serum ascorbic acid concentrations by HPLC and to genotype for two SVCT1 (rs4257763 and rs6596473) and two SVCT2 (rs6139591 and rs2681116) polymorphisms. No diet-gene interactions were observed for the vitamin C transporter polymorphisms, however, the average (mean+/-SE) serum ascorbic acid concentrations differed between rs4257763 genotypes (GG: 24.4+/-1.3, GA: 26.8+/-1.1, AA: 29.7+/-1.4 micromol/l; p=0.002). For this polymorphism, the correlation between dietary vitamin C and serum ascorbic acid was only significant in subjects with a G allele. The SVCT2 polymorphisms also appeared to modify the strength of the diet-serum correlation. Our findings demonstrate that genetic variation in SVCT1 can influence serum ascorbic acid concentrations and that SVCT1 and SVCT2 genotypes modify the strength of the correlation between dietary vitamin C and serum ascorbic acid. Copyright © 2010 S. Karger AG, Basel.

Supplement of a chitosan and ascorbic acid mixture for Crohn's disease: a pilot study.

PubMed

Tsujikawa, Tomoyuki; Kanauchi, Osamu; Andoh, Akira; Saotome, Takao; Sasaki, Masaya; Fujiyama, Yoshihide; Bamba, Tadao

2003-02-01

Although the pathogenesis of Crohn's disease remains unclear, dietary fat is thought to exacerbate intestinal inflammation. Chitosan is a water-insoluble dietary fiber, and a chitosan and ascorbic acid mixture has been shown in rats to increase fecal fat excretion without affecting protein digestibility. However, it remains unclear whether a chitosan and ascorbic acid mixture is safe and effective for patients with Crohn's disease. We designed a pilot trial to investigate the tolerability and amount of fat excretion after the oral administration of a chitosan and ascorbic mixture for inactive Crohn's disease. Eleven outpatients were given seven tablets daily of a chitosan and ascorbic mixture (chitosan was given at 1.05 g/d) for 8 wk. Patients did not interrupt their respective therapies for Crohn's disease. The bowel movements of most patients increased slightly during the study. Nutritional and inflammatory markers in patients did not differ before and after treatment. The chitosan and ascorbic acid mixture significantly increased the fat concentration in the feces during treatment. These results indicated that oral administration of a chitosan and ascorbic acid mixture in patients with Crohn's disease is tolerable and increases fecal fat excretion without affecting disease activity.

Effect of stationary magnetic field strengths of 150 and 200 mT on reactive oxygen species production in soybean.

PubMed

Shine, M B; Guruprasad, K N; Anand, Anjali

2012-07-01

Our previous investigation reported the beneficial effect of pre-sowing magnetic treatment for improving germination parameters and biomass accumulation in soybean. In this study, soybean seeds treated with static magnetic fields of 150 and 200 mT for 1 h were evaluated for reactive oxygen species (ROS) and activity of antioxidant enzymes. Superoxide and hydroxyl radicals were measured in embryos and hypocotyls of germinating seeds by electron paramagnetic resonance spectroscopy and kinetics of superoxide production; hydrogen peroxide and antioxidant activities were estimated spectrophotometrically. Magnetic field treatment resulted in enhanced production of ROS mediated by cell wall peroxidase while ascorbic acid content, superoxide dismutase and ascorbate peroxidase activity decreased in the hypocotyl of germinating seeds. An increase in the cytosolic peroxidase activity indicated that this antioxidant enzyme had a vital role in scavenging the increased H(2)O(2) produced in seedlings from the magnetically treated seeds. Hence, these studies contribute to our first report on the biochemical basis of enhanced germination and seedling growth in magnetically treated seeds of soybean in relation to increased production of ROS. Copyright © 2012 Wiley Periodicals, Inc.

Effects of Acifluorfen on Endogenous Antioxidants and Protective Enzymes in Cucumber (Cucumis sativus L.) Cotyledons

PubMed Central

Kenyon, William H.; Duke, Stephen O.

1985-01-01

The herbicide acifluorfen (2-chloro-4-(trifluoromethyl)phenoxy-2-nitrobenzoate) causes strong photooxidative destruction of pigments and lipids in sensitive plant species. Antioxidants and oxygen radical scavengers slow the bleaching action of the herbicide. The effect of acifluorfen on glutathione and ascorbate levels in cucumber (Cucumis sativus L.) cotyledon discs was investigated to assess the relationship between herbicide activity and endogenous antioxidants. Acifluorfen decreased the levels of glutathione and ascorbate over 50% in discs exposed to less than 1.5 hours of white light (450 microeinsteins per square meter per second). Coincident increases in dehydroascorbate and glutathione disulfide were not observed. Acifluorfen also caused the rapid depletion of ascorbate in far-red light grown plants which were photosynthetically incompetent. Glutathione reductase, dehydroascorbate reductase, superoxide dismutase, ascorbate oxidase, ascorbate free radical reductase, peroxidase, and catalase activities rapidly decreased in acifluorfen-treated tissue exposed to white light. None of the enzymes were inhibited in vitro by the herbicide. Acifluorfen causes irreversible photooxidative destruction of plant tissue, in part, by depleting endogenous antioxidants and inhibiting the activities of protective enzymes. PMID:16664506

Ethylene Response Factor TERF1, Regulated by ETHYLENE-INSENSITIVE3-like Factors, Functions in Reactive Oxygen Species (ROS) Scavenging in Tobacco (Nicotiana tabacum L.).

PubMed

Zhang, Hongbo; Li, Ang; Zhang, Zhijin; Huang, Zejun; Lu, Pingli; Zhang, Dingyu; Liu, Xinmin; Zhang, Zhong-Feng; Huang, Rongfeng

2016-07-20

The phytohormone ethylene plays a crucial role in the production and accumulation of reactive oxygen species (ROS) in plants under stress conditions. Ethylene response factors (ERFs) are important ethylene-signaling regulators functioning in plant defense responses against biotic and abiotic stresses. However, the roles of ERFs during plant adapting to ROS stress have not yet been well documented. Our studies previously reported that a tomato ERF transcription factor TERF1 functions in the regulation of plant ethylene responses and stress tolerance. Here, we report our findings regarding the roles of TERF1 in ROS scavenging. In this study, we revealed that the transcription of TERF1 is regulated by upstream EIN3-like (EIN3, ethylene-insensitive 3) regulators LeEIL3 and LeEIL4 in tomato (Solanum lycopersicum), and is also inducible by exogenous applied ROS-generating reagents. Ectopic expression of TERF1 in tobacco promoted the expression of genes involved in oxidative stress responses, including carbonic anhydrase functioning in hypersensitive defense, catalase and glutathione peroxidase catalyzing oxidative reactions, and GDP-D-mannose pyrophosphorylase functioning in ascorbic acid biosynthesis, reduced the ROS content induced by ethylene treatment, and enhanced stress tolerance of tobacco seedlings to hydrogen peroxide (H2O2). Cumulatively, these findings suggest that TERF1 is an ethylene inducible factor regulating ROS scavenging during stress responses.

The Effect of Ascorbic Acid and Garlic Administration on Lead-Induced Neural Damage in Rat Offspring's Hippocampus.

PubMed

Sadeghi, Akram; Ebrahimzadeh Bideskan, Alireza; Alipour, Fatemeh; Fazel, Alireza; Haghir, Hossein

2013-02-01

The aim of this study was to investigate ascorbic acid and garlic protective effects on lead-induced neurotoxicity during rat hippocampus development. 90 pregnant wistar rats were divided randomly into nine groups: 1- Animals received leaded water (L). 2- Rats received leaded water and ascorbic acid (L+AA). 3- Animals received leaded water and garlic juice (L+G). 4-Animals received leaded water, ascorbic acid and garlic juice (L+G+AA). 5- Rats treated with ascorbic acid (AA). 6- Rats treated with garlic juice (G). 7- Rats treated with ascorbic acid and garlic juice (AA+G). 8- Rats treated with tap water plus 0.4 ml/l normal hydrogen chloride (HCl) and 0.5 mg/l Glucose (Sham). 9- Normal group (N). Leaded water (1500 ppm), garlic juice (1 ml/100g/day, gavage) and ascorbic acid (500 mg/kg/day, IP) were used. Finally, blood lead levels (BLL) were measured in both rats and their offspring. The rat offspring brain sections were stained using Toluidine Blue and photographed. Dark neurons (DNs) were counted to compare all groups. BLL significantly increased in L group compared to control and sham groups and decreased in L+G and L+AA groups in comparison to the L group (P<0.05). the number of DNs in the CA1, CA3, and DG of rat offspring hippocampus significantly increased in L group in comparison to control and sham groups (P<0.05) and decreased in L+G and L+AA groups compared to L group (P<0.05). Garlic juice and ascorbic acid administration during pregnancy and lactation may protect lead-induced neural damage in rat offspring hippocampus.

Determination of the phenolic content and antioxidant potential of crude extracts and isolated compounds from leaves of Cordia multispicata and Tournefortia bicolor.

PubMed

Correia Da Silva, Thiago B; Souza, Vivian Karoline T; Da Silva, Ana Paula F; Lyra Lemos, Rosangela P; Conserva, Lucia M

2010-01-01

In this work, the total phenolic content and antioxidant activity of extracts and four flavonoids isolated from leaves of two Boraginaceae species (Cordia multispicata Cham. and Tournefortia bicolor Sw.) were evaluated using Folin-Ciocalteu reagent, DPPH free radical scavenging and inhibition of peroxidation of linoleic acid by FTC method. For comparison, ascorbic acid, alpha-tocopherol and BHT were used. In general, extracts from T. bicolor (68.8 +/- 0.001 to > 1000 mg/g) showed higher phenolic content than C. multispicata (66.1 +/- 0.009 to 231 +/- 0.07 mg/g), and also scavenged radicals (IC(50) 12.8 +/- 2.5 to 437 +/- 3.5 mg/L) and inhibited lipid peroxide formation (IC(50) 51.2 +/- 2.29 to 89 +/- 0.59 mg/L). For these extracts a good correlation between the phenolic content and antioxidant activity was observed, suggesting that T. bicolor is richer in phenolic compounds and that it could serve as a new source of natural antioxidants or nutraceuticals with potential applications. Chromatographic procedures monitored by antioxidant assays afforded seven compounds, which were identified by spectral analyses (IR, MS and 1D and 2D NMR) and comparison with reported data as being trans-phytol (1), taraxerol (2), 3,7,4'-trimethoxyflavone (3), 5,3'-dihydroxy-3,7,4'-trimethoxyflavone (4), quercetin (5), tiliroside (6), and rutin (7). Compounds (4-7) were also evaluated and were effective as DPPH quenching (IC(50) 7.7 +/- 3.6 to 79.3 +/- 3.4 mg/L) and as inhibition of lipid peroxidation (IC(50) 80.1 +/- 0.98 to 88.7 +/- 3.62 mg/L). This is the first report on the total phenolic content, radical-scavenging and antioxidant activities of these species.

Hepatoprotective and antioxidant activity of Phaseolus trilobus, Ait on bile duct ligation induced liver fibrosis in rats.

PubMed

Fursule, R A; Patil, S D

2010-06-16

Phaseolus trilobus Ait (Fabaceae) is extensively used by tribal people of Nandurbar district (Maharashtra, India) in the treatment of Jaundice and other liver disorders. of the present study was to assess the medicinal claim of Phaseolus trilobus as hepatoprotective and antioxidant. The hepatoprotective activity of methanol and aqueous extract of Phaseolus trilobus was evaluated by bile duct ligation induced liver fibrosis and antioxidant activity was evaluated using in vitro and in vivo antioxidant models viz anti-lipid peroxidation assay, super oxide radical scavenging assay and glutathione estimation in liver. Liver function tests were carried out to detect hepatoprotective activity, which was further supported by histopathological examination. Methanol and aqueous extracts of Phaseolus trilobus reduced elevated level of alanine aminotransferase (ALT), aspartate aminotransferase (AST), alkaline phosphatase (ALP), lactate dehydrogenase (LDH), bilirubin and hydroxyproline significantly (p<0.01) in bile duct ligated Wistar rats, proving hepatoprotective activity comparable with Silymarin. Both the extracts were found to reduce the elevated levels of serum thiobarbituric acid reactive substance (TBARS) and elevate superoxide scavenging radical activity proving antioxidant activity comparable with ascorbic acid. The reduced level of glutathione was found to be elevated in liver proving antioxidant activity comparable with Silymarin. Phaseolus trilobus posses hepatoprotective property and is effective in oxidative stress induced cholestatic hepatic injury. Copyright 2010 Elsevier Ireland Ltd. All rights reserved.

Jatropha curcas leaf and bark fractions protect against ultraviolet radiation-B induced DNA damage in human peripheral blood lymphocytes.

PubMed

Sundari, J; Selvaraj, R; Rajendra Prasad, N; Elumalai, R

2013-11-01

The present study is conducted to investigate the antioxidant potential of Jatropha curcas root bark extract (RB4 fraction) and leaf extract (L1 fraction), and to study their effects on UVB-radiation-induced DNA damage in cultured human blood lymphocytes. In this study, J. curcas showed strong antioxidant property in different free radical scavenging systems. Both the fractions effectively scavenged hydroxyl (OH), superoxide anion (O₂(·-)), 1,1-diphenyl-2-picrylhydrazyl (DPPH·) and 2,2-azino-bis-3-ethylbenzothiazoline-6-sulphonic acid radical cation (ABTS(·+)) in a concentration-dependent manner. The IC₅₀ (Inhibitory Concentration 50) values of J. curcas fractions were compared to standard ascorbic acid used in this study. The antioxidant potential of a compound was directly proportional to the photoprotective effect. In this study, human peripheral blood lymphocytes (HPBL) were exposed to UVB-radiation and there was an increase in comet attributes (% tail DNA, tail length, tail movement and Olive tail moment). Jatropha curcas RB4 fraction and L1 fraction treatment before UVB-irradiation significantly decreased the % tail DNA, tail length, tail moment and Olive tail moment in irradiated HPBL. These results suggested that J. curcas exhibited strong antioxidant property and RB4 and L1 fractions protected UVB-radiation-induced DNA damage in HPBL. Copyright © 2013 Elsevier B.V. All rights reserved.

Optimisation of supercritical carbon dioxide extraction of essential oil of flowers of tea (Camellia sinensis L.) plants and its antioxidative activity.

PubMed

Chen, Zhenchun; Mei, Xin; Jin, Yuxia; Kim, Eun-Hye; Yang, Ziyin; Tu, Youying

2014-01-30

To extract natural volatile compounds from tea (Camellia sinensis) flowers without thermal degradation and residue of organic solvents, supercritical fluid extraction (SFE) using carbon dioxide was employed to prepare essential oil of tea flowers in the present study. Four important parameters--pressure, temperature, static extraction time, and dynamic extraction time--were selected as independent variables in the SFE. The optimum extraction conditions were the pressure of 30 MPa, temperature of 50°C, static time of 10 min, and dynamic time of 90 min. Based on gas chromatography-mass spectrometry analysis, 59 compounds, including alkanes (45.4%), esters (10.5%), ketones (7.1%), aldehydes (3.7%), terpenes (3.7%), acids (2.1%), alcohols (1.6%), ethers (1.3%) and others (10.3%) were identified in the essential oil of tea flowers. Moreover, the essential oil of tea flowers showed relatively stronger DPPH radical scavenging activity than essential oils of geranium and peppermint, although its antioxidative activity was weaker than those of essential oil of clove, ascorbic acid, tert-butylhydroquinone, and butylated hydroxyanisole. Essential oil of tea flowers using SFE contained many types of volatile compounds and showed considerable DPPH scavenging activity. The information will contribute to the future application of tea flowers as raw materials in health-care food and food flavour industries. © 2013 Society of Chemical Industry.

From sequence analysis of three novel ascorbate peroxidases from Arabidopsis thaliana to structure, function and evolution of seven types of ascorbate peroxidase.

PubMed Central

Jespersen, H M; Kjaersgård, I V; Ostergaard, L; Welinder, K G

1997-01-01

Ascorbate peroxidases are haem proteins that efficiently scavenge H2O2 in the cytosol and chloroplasts of plants. Database analyses retrieved 52 expressed sequence tags coding for Arabidopsis thaliana ascorbate peroxidases. Complete sequencing of non-redundant clones revealed three novel types in addition to the two cytosol types described previously in Arabidopsis. Analysis of sequence data available for all plant ascorbate peroxidases resulted in the following classification: two types of cytosol soluble ascorbate peroxidase designated cs1 and cs2; three types of cytosol membrane-bound ascorbate peroxidase, namely cm1, bound to microbodies via a C-terminal membrane-spanning segment, and cm2 and cm3, both of unknown location; two types of chloroplast ascorbate peroxidase with N-terminal transit sequences, the stromal ascorbate peroxidase (chs), and the thylakoid-bound ascorbate peroxidase showing a C-terminal transmembrane segment and designated cht. Further comparison of the patterns of conserved residues and the crystal structure of pea ascorbate peroxidase showed that active site residues are conserved, and three peptide segments implicated in interaction with reducing substrate are similar, excepting cm2 and cm3 types. A change of Phe-175 in cytosol types to Trp-175 in chloroplast types might explain the greater ascorbate specificity of chloroplast compared with cytosol ascorbate peroxidases. Residues involved in homodimeric subunit interaction are conserved only in cs1, cs2 and cm1 types. The proximal cation (K+)-binding site observed in pea ascorbate peroxidase seems to be conserved. In addition, cm1, cm2, cm3, chs and cht ascorbate peroxidases contain Asp-43, Asn-57 and Ser-59, indicative of a distal monovalent cation site. The data support the hypothesis that present-day peroxidases evolved by an early gene duplication event. PMID:9291097

Overexpression of an alfalfa GDP-mannose 3, 5-epimerase gene enhances acid, drought and salt tolerance in transgenic Arabidopsis by increasing ascorbate accumulation.

PubMed

Ma, Lichao; Wang, Yanrong; Liu, Wenxian; Liu, Zhipeng

2014-11-01

GDP-mannose 3', 5'-epimerase (GME) catalyses the conversion of GDP-D-mannose to GDP-L-galactose, an important step in the ascorbic acid (ascorbic acid) biosynthetic pathway in higher plants. In this study, a novel cDNA fragment (MsGME) encoding a GME protein was isolated and characterised from alfalfa (Medicago sativa). An expression analysis confirmed that MsGME expression was induced by salinity, PEG and acidity stresses. MsGME overexpression in Arabidopsis enhanced tolerance of the transgenic plants to salt, drought and acid. Real-time PCR analysis revealed that the transcript levels of GDP-D-mannose pyrophosphorylase (GMP), L-galactose-phosphate 1-P phosphatase (GP) and GDP-L-galactose phosphorylase (GGP) were increased in transgenic Arabidopsis (T3 generation). Moreover, the ascorbate content was increased in transgenic Arabidopsis. Our results suggest that MsGME can effectively enhance tolerance of transgenic Arabidopsis to acid, drought and salt by increasing ascorbate accumulation.

Investigation of atmospheric oxidation of propyl gallate in an anionic surfactant system in the absence and presence of ascorbic acid.

PubMed

Szymula, M

2004-01-01

The antioxidant efficiency of two hydrophilic species, ascorbic acid (AA) and propyl gallate (PG), in an anionic surfactant system are studied. Ascorbic acid and propyl gallate are dissolved/solubilized in a microemulsion formed by water, pentanol, and sodium dodecyl sulfate. The determination of propyl gallate decomposition/oxidation kinetics shows enhanced oxidation of PG with increasing pentanol concentration in the system. When ascorbic acid and propyl gallate are both present in water, in surfactant aqueous solution, and in the studied microemulsion systems, the molecular complex AAPG is formed. After some time the complex decomposes.

Ascorbic acid supplementation enhances recovery from ethanol induced inhibition of Leydig cell steroidogenesis than abstention in male guinea pigs.

PubMed

Radhakrishnakartha, Harikrishnan; Appu, Abhilash Puthuvelvippel; Indira, Madambath

2014-01-15

The impact of ascorbic acid supplementation against ethanol induced Leydig cell toxicity was studied in guinea pigs. Male guinea pigs were exposed to ethanol (4g/kgb.wt.) for 90 days. After 90 days, ethanol administration was completely stopped and animals in the ethanol group were divided into abstention group and ascorbic acid supplemented group (25mg/100gb.wt.) and those in control group were maintained as control and control+ascorbic acid group. Ethanol administration reduced the serum testosterone and LH (luteinising hormone) levels and elevated estradiol levels. Cholesterol levels in Leydig cell were increased whereas the mRNA and protein expressions of StAR (steroidogenic acute regulatory) protein, cytochrome P450scc (cytochrome p450side chain cleavage enzyme), 3β-HSD (3β-hydroxysteroid dehydrogenase), 17β-HSD (17β-hydroxysteroid dehydrogenase) and LH receptor were drastically reduced. Administration of ascorbic acid resulted in alteration of all these parameters indicating enhanced recovery from ethanol induced inhibition of Leydig cell steroidogenesis. Although abstention could also reduce the inhibition of steroidogenesis, this was lesser in comparison with ascorbic acid supplemented group. © 2013 Published by Elsevier B.V.

Dietary taurine alters ascorbic acid metabolism in rats fed diets containing polychlorinated biphenyls.

PubMed

Mochizuki, H; Oda, H; Yokogoshi, H

2000-04-01

The effect of dietary taurine on ascorbic acid metabolism and hepatic drug-metabolizing enzymes was investigated in rats fed diets containing polychlorinated biphenyls (PCB) to determine whether taurine has an adaptive and protective function in xenobiotic-treated animals. Young male Wistar rats (60 g) were fed diets containing 0 or 0.2 g/kg diet PCB with or without 30 g/kg diet of taurine for 14 d. The rats fed the PCB-containing diets had greater liver weight, higher ascorbic acid concentrations in the liver and spleen and greater hepatic cytochrome P-450 contents than control rats that were not treated with PCB (P < 0.01). In PCB-fed rats, urinary ascorbic acid excretion was enhanced, and serum cholesterol concentration (especially HDL-cholesterol) was significantly elevated compared with those in control rats. Dietary taurine significantly potentiated the increases in the urinary excretion of ascorbic acid and the rise in the levels of cytochrome P-450 which were caused by PCB treatment. On the other hand, the supplementation of taurine to control diet did not alter these variables. Taurine may enhance the hepatic drug-metabolizing systems, leading to the stimulation of the ascorbic acid metabolism in rats fed diets containing PCB.

New β-Cyclodextrin Entrapped in Polyethyleneimine Film-Modified Electrodes for Pharmaceutical Compounds Determination

PubMed Central

Fritea, Luminţa; Tertiş, Mihaela; Cristea, Cecilia; Săndulescu, Robert

2013-01-01

The electrochemical behavior of ascorbic acid and uric acid on glassy carbon bare electrodes and ones modified with β-cyclodextrin entrapped in polyethyleneimine film has been investigated using square wave voltammetry. The electrode modification was achieved in order to separate the voltammetric peaks of ascorbic acid and uric acid when present in the same solution. On the modified electrodes the potential of the oxidation peak of the ascorbic acid was shifted to more negative values by over 0.3 V, while in the case of uric acid, the negative potential shift was about 0.15 V compared to the bare glassy carbon electrode. When the two compounds were found together in the solution, on the bare electrode only a single broad signal was observed, while on the modified electrode the peak potentials of these two compounds were separated by 0.4 V. When the uric acid concentration remained constant, the peak intensity of the ascorbic acid is increased linearly with the concentration (r2 = 0.996) and when the ascorbic acid concentration remains constant, the peak intensity of the uric acid increased linearly with the concentration (r2 = 0.992). FTIR measurements supported the formation of inclusion complexes. In order to characterize the modification of the electrodes microscopic studies were performed. The modified electrodes were successfully employed for the determination of ascorbic acid in pharmaceutical formulations with a detection limit of 0.22 μM. PMID:24287544

Inhibition of Human Amylin Aggregation and Cellular Toxicity by Lipoic Acid and Ascorbic Acid.

PubMed

Azzam, Sarah Kassem; Jang, Hyunwoo; Choi, Myung Chul; Alsafar, Habiba; Lukman, Suryani; Lee, Sungmun

2018-04-30

More than 30 human degenerative diseases result from protein aggregation such as Alzheimer's disease (AD) and type 2 diabetes mellitus (T2DM). Islet amyloid deposits, a hallmark in T2DM, are found in pancreatic islets of more than 90 % of T2DM patients. An association between amylin aggregation and reduction in β-cell mass was also established by post-mortem studies. A strategy in preventing protein aggregation-related disorders is to inhibit the protein aggregation and associated toxicity. In this study we demonstrated that two inhibitors, lipoic acid and ascorbic acid, significantly inhibited amylin aggregation. Compared to amylin (15 μM) as 100 %, lipoic acid and ascorbic acid reduced amylin fibril formation to 42.1 ± 17.2 % and 42.9 ± 12.8 % respectively, which is confirmed by fluorescence and TEM images. In cell viability tests, both inhibitors protected RIN-m5f β-cells from the toxicity of amylin aggregates. At 10:1 molar ratio of lipoic acid to amylin, lipoic acid with amylin increased the cell viability to 70.3 %, whereas only 42.8 % RIN-m5f β-cells survived in amylin aggregates. For ascorbic acid, an equimolar ratio achieved the highest cell viability of 63.3 % as compared to 42.8 % with amylin aggregates only. Docking results showed that lipoic acid and ascorbic acid physically interact with amylin amyloidogenic region (residues Ser20-Ser29) via hydrophobic interactions; hence reducing aggregation levels. Therefore, lipoic acid and ascorbic acid prevented amylin aggregation via hydrophobic interactions, which resulted in the prevention of cell toxicity in vitro.

21 CFR 182.3013 - Ascorbic acid.

Code of Federal Regulations, 2010 CFR

2010-04-01

... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Ascorbic acid. 182.3013 Section 182.3013 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) FOOD FOR HUMAN CONSUMPTION (CONTINUED) SUBSTANCES GENERALLY RECOGNIZED AS SAFE Chemical Preservatives § 182.3013 Ascorbic...

Physico-Chemical Characterization, Bioactive Compounds and Antioxidant Activity of Malay Apple [Syzygium malaccense (L.) Merr. & L.M. Perry

PubMed Central

Nunes, Polyana Campos; Aquino, Jailane de Souza; Rockenbach, Ismael Ivan; Stamford, Tânia Lúcia Montenegro

2016-01-01

The purpose of this study was to evaluate the physico-chemical characteristics, bioactive compounds and antioxidant activity of Malay apple fruit (Syzygium malaccense) grown in Brazil with regard to the geographical origin and its peel fractions and edible portion analyzed independently. Fruit diameter, weight, yield, and centesimal composition, ascorbic acid, reductive sugars, total soluble solids, pH and fiber content were determined. Total phenolics (1293 mg gallic acid equivalent/100 g) and total anthocyanins (1045 mg/100 g) contents were higher in the peel, with the major anthocyanin identified using HPLC-DAD-MS/MS as cyanidin 3-glucoside. Higher values for DPPH antiradical scavenging activity (47.52 μMol trolox equivalent antioxidant capacity/g) and Ferric Reducing Antioxidant Potential (FRAP, 0.19 mM ferreous sulfate/g) were also observed in the peel fraction. All extracts tested showed the ability to inhibit oxidation in the β-carotene/linoleic acid system. This study highlights the potential of Malay apple fruit as a good source of antioxidant compounds with potential benefits to human health. PMID:27352306

Sequestering ability of butylated hydroxytoluene, propyl gallate, resveratrol, and vitamins C and E against ABTS, DPPH, and hydroxyl free radicals in chemical and biological systems.

PubMed

Soares, Daniele G; Andreazza, Ana C; Salvador, Mirian

2003-02-12

The antioxidant capacity of butylated hydroxytoluene (BHT; 2,6-di-tert-butyl-p-cresol), propyl gallate (3,4,5-trihydroxybenzoic acid n-propyl ester), resveratrol (trans-3,4',5-trihydroxystilbene), and vitamins C (l-ascorbic acid) and E [(+)-alpha-tocopherol] was studied in chemical and biological systems. The chemical assays evaluated the capacity of these antioxidants to sequester 2,2'-azinobis(3-ethylbenzthiazoline-6-sulfonic acid) (ABTS.) and 1,1 diphenyl-2-picrylhydrazyl (DPPH.). A new colorimetric method to determine hydroxyl radical scavenging is also described. The biological tests use the eucaryotic cells of Saccharomyces cerevisiae treated with the antioxidants in the presence of the stressing agents apomorphine, hydrogen peroxide, and paraquat dichloride (methylviologen; 1,1'-dimethyl-4,4'-bipyridinium dichloride). The results in chemical systems showed that all of the antioxidants were able to significantly inhibit the oxidation of beta-carotene by hydroxyl free radicals. The assays in yeast showed that the antioxidant activity of the tested compounds depended on the stressing agent used and the mechanism of action of the antioxidant.

Morphological, physicochemical, and antioxidant profile of noncommercial banana cultivars

PubMed Central

Anyasi, Tonna A; Jideani, Afam IO; Mchau, Godwin A

2015-01-01

Banana cultivars––Luvhele (MusaABB), Mabonde (MusaAAA), and Muomva-red (Musa balbisiana) ––were characterized for morphological, physicochemical, and antioxidant properties. All three cultivars varied significantly (P < 0.05) in their morphology, pH, titratable acidity and total soluble solids with no significant difference in their ash content. Individual cultivars showed variations in flour starch granule when observed using a scanning electron microscope. Characterization of cultivars for total polyphenols (TPs) and antioxidant activity upon pretreatment with ascorbic, citric, and lactic acid shows that the 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical scavenging assay of samples varied significantly as Muomva-red cultivar (1.02 ± 0.01 mg GA/g) expressed the highest DPPH activity at lactic acid concentration of 20 g/L. Total polyphenol content was also highest for Muomva-red [1091.76 ± 122.81 mg GAE/100 g (d.w.)]. The high amount of TPs present in these cultivars make them suitable source of bio-nutrients with great medicinal and health functions. PMID:25987997

Chemical repair activity of free radical scavenger edaravone: reduction reactions with dGMP hydroxyl radical adducts and suppression of base lesions and AP sites on irradiated plasmid DNA.

PubMed

Hata, Kuniki; Urushibara, Ayumi; Yamashita, Shinichi; Lin, Mingzhang; Muroya, Yusa; Shikazono, Naoya; Yokoya, Akinari; Fu, Haiying; Katsumura, Yosuke

2015-01-01

Reactions of edaravone (3-methyl-1-phenyl-2-pyrazolin-5-one) with deoxyguanosine monophosphate (dGMP) hydroxyl radical adducts were investigated by pulse radiolysis technique. Edaravone was found to reduce the dGMP hydroxyl radical adducts through electron transfer reactions. The rate constants of the reactions were greater than 4 × 10(8) dm(3) mol(-1) s(-1) and similar to those of the reactions of ascorbic acid, which is a representative antioxidant. Yields of single-strand breaks, base lesions, and abasic sites produced in pUC18 plasmid DNA by gamma ray irradiation in the presence of low concentrations (10-1000 μmol dm(-3)) of edaravone were also quantified, and the chemical repair activity of edaravone was estimated by a method recently developed by the authors. By comparing suppression efficiencies to the induction of each DNA lesion, it was found that base lesions and abasic sites were suppressed by the chemical repair activity of edaravone, although the suppression of single-strand breaks was not very effective. This phenomenon was attributed to the chemical repair activity of edaravone toward base lesions and abasic sites. However, the chemical repair activity of edaravone for base lesions was lower than that of ascorbic acid. © The Author 2014. Published by Oxford University Press on behalf of The Japan Radiation Research Society and Japanese Society for Radiation Oncology.

Flash photo stimulation of human neural stem cells on graphene/TiO2 heterojunction for differentiation into neurons

NASA Astrophysics Data System (ADS)

Akhavan, Omid; Ghaderi, Elham

2013-10-01

For the application of human neural stem cells (hNSCs) in neural regeneration and brain repair, it is necessary to stimulate hNSC differentiation towards neurons rather than glia. Due to the unique properties of graphene in stem cell differentiation, here we introduce reduced graphene oxide (rGO)/TiO2 heterojunction film as a biocompatible flash photo stimulator for effective differentiation of hNSCs into neurons. Using the stimulation, the number of cell nuclei on rGO/TiO2 increased by a factor of ~1.5, while on GO/TiO2 and TiO2 it increased only ~48 and 24%, respectively. Moreover, under optimum conditions of flash photo stimulation (10 mW cm-2 flash intensity and 15.0 mM ascorbic acid in cell culture medium) not only did the number of cell nuclei and neurons differentiated on rGO/TiO2 significantly increase (by factors of ~2.5 and 3.6), but also the number of glial cells decreased (by a factor of ~0.28). This resulted in a ~23-fold increase in the neural to glial cell ratio. Such highly accelerated differentiation was assigned to electron injection from the photoexcited TiO2 into the cells on the rGO through Ti-C and Ti-O-C bonds. The role of ascorbic acid, as a scavenger of the photoexcited holes, in flash photo stimulation was studied at various concentrations and flash intensities.

Theoretical investigation of generator-collector microwell arrays for improving electroanalytical selectivity: application to selective dopamine detection in the presence of ascorbic acid.

PubMed

Oleinick, Alexander; Zhu, Feng; Yan, Jiawei; Mao, Bingwei; Svir, Irina; Amatore, Christian

2013-06-24

Recessed generator-collector assemblies consisting of an array of recessed disks (generator electrodes) with a gold layer (collector electrode) deposited over the top-plane insulator reportedly allow increased selectivity and sensitivity during electrochemical detection of dopamine (DA) in the presence of ascorbic acid (AA), a situation which is frequently encountered. In sensor design, the potential of the disk electrodes is set to the wave plateau of DA, whereas the plane electrode is biased at the irreversible wave plateau of AA before the onset of the DA oxidation wave. Thus, AA is scavenged but DA is allowed to enter the nanocavities to be oxidized at the disk electrodes, and its signal is further amplified by redox cycling between disk and plane electrodes. Several different theoretical approaches are elaborated herein to analyze the behavior of the system, and their conclusions are successfully tested by experiments. This reveals the crucial role of the plane-electrode area which screens access to the recessed disks (i.e. acts as a diffusional Faraday cage) and simultaneously contributes to amplification of the analyte signal through positive feedback, as occurs in interdigitated arrays and scanning electrochemical microscopy. Simulations also allow for the evaluation of the benefits of different geometries inspired by the above design and different operating modes for increasing the sensor performance. Copyright © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Ascorbic acid deficiency leads to increased grain chalkiness in transgenic rice for suppressed of L-GalLDH.

PubMed

Yu, Le; Liu, Yonghai; Lu, Lina; Zhang, Qilei; Chen, Yezheng; Zhou, Liping; Chen, Hua; Peng, Changlian

2017-04-01

The grain chalkiness of rice (Oryza sativa L.), which determines the rice quality and price, is a major concern in rice breeding. Reactive oxygen species (ROS) plays a critical role in regulating rice endosperm chalkiness. Ascorbic acid (Asc) is a major plant antioxidant, which strictly regulates the levels of ROS. l-galactono-1, 4-lactone dehydrogenase (L-GalLDH, EC 1.3.2.3) is an enzyme that catalyzes the last step of Asc biosynthesis in higher plants. Here we show that the L-GalLDH-suppressed transgenic rice, GI-1 and GI-2, which have constitutively low (between 30% and 50%) leaf and grain Asc content compared with the wild-type (WT), exhibit significantly increased grain chalkiness. Further examination showed that the deficiency of Asc resulted in a higher lipid peroxidation and H 2 O 2 content, accompanied by a lower hydroxyl radical scavenging rate, total antioxidant capacity and photosynthetic ability. In addition, changes of the enzyme activities and gene transcript abundances related to starch synthesis were also observed in GI-1 and GI-2 grains. The results we presented here suggest a close correlation between Asc deficiency and grain chalkiness in the L-GalLDH-suppressed transgenics. Asc deficiency leads to the accumulation of H 2 O 2 , affecting antioxidant capacity and photosynthetic function, changing enzyme activities and gene transcript abundances related to starch synthesis, finally leading to the increased grain chalkiness. Copyright © 2017 Elsevier GmbH. All rights reserved.

Activation energy determinations suggest that thiols reverse autooxidation of tetrahydrobiopterin by a different mechanism than ascorbate.

PubMed

Valent, Sándor; Tóth, Miklós

2006-01-01

In neutral aqueous solutions tetrahydrobiopterin is oxidized by dioxygen in a reaction that is succinctly described as autooxidation. Ascorbate and thiols moderate this reaction by reversing the oxidative process. In the present study the effect of various thiols on the apparent Arrhenius activation energy of tetrahydrobiopterin autooxidation was characterized and compared to that of ascorbate determined previously. We observed that - in sharp contrast to ascorbate - the efficiency of thiols to protect tetrahydrobiopterin decreased with the elevation of temperature from 22 to 37 degrees C. Accordingly, the apparent Arrhenius activation energies (in kJ/mol) measured in the presence of thiols were consistently greater than the value determined with tetrahydrobiopterin alone (59.6 +/- 1.4) or in the presence of ascorbate (59.9 +/- 2.8). Thus, the energy values were 88.8+/-1.1 with glutathione, 87.6 +/- 2.1 with N-acetylcysteine, 79.2 +/- 1.6 with cysteine, 75.1 +/- 2.4 with dithiotreitol and 70.3 +/- 0.9 with homocysteine. Since thiols are as potent reducing agents as ascorbate, these findings suggest that thiols and ascorbate protect tetrahydrobiopterin from oxidation acting at different steps of the oxidation process. It is likely that thiols reduce quinoidal dihydrobiopterin, whereas ascorbate scavenges the trihydrobiopterin radical to tetrahydrobiopterin. Furthermore, the results indicate that thiols are excellent tools to protect tetrahydrobiopterin from autooxidative decomposition in laboratory experiments conducted at relatively low temperatures, whereas the protective effect diminishes at 37 degrees C, i.e. under physiological conditions.

Sonication improves kasturi lime (Citrus microcarpa) juice quality.

PubMed

Bhat, Rajeev; Kamaruddin, Nor Shuaidda Bt Che; Min-Tze, Liong; Karim, A A

2011-11-01

Freshly squeezed kasturi lime fruit juice was sonicated (for 0, 30 and 60min at 20°C, 25kHz frequency) to evaluate its impact on selected physico-chemical and antioxidant properties, such as pH, °Brix, titratable acidity, Hunter color values (L(∗), a(∗), b(∗)), ascorbic acid, DPPH radical scavenging activity, total phenolics, antioxidant capacity, flavonoids and flavonols. Additionally, the effect of sonication treatments on the microbial load (TPC, yeast and mold) were also evaluated. Sonication of juice samples for 60min showed enhancement in most of the bioactive compounds compared to samples treated for 30min and control samples (untreated). Significant reductions in the microbial load corresponding to sonication time were also recorded. Results of the present study indicate that sonication may be employed as a suitable technique for kasturi lime juice processing, where antioxidant and other bioactive compound retention or enhancement is desired, along with the achievement of safety and quality standards. Copyright © 2011 Elsevier B.V. All rights reserved.

Targeting excessive free radicals with peels and juices of citrus fruits: grapefruit, lemon, lime and orange.

PubMed

Guimarães, Rafaela; Barros, Lillian; Barreira, João C M; Sousa, M João; Carvalho, Ana Maria; Ferreira, Isabel C F R

2010-01-01

A comparative study between the antioxidant properties of peel (flavedo and albedo) and juice of some commercially grown citrus fruit (Rutaceae), grapefruit (Citrus paradisi), lemon (Citrus limon), lime (Citrusxaurantiifolia) and sweet orange (Citrus sinensis) was performed. Different in vitro assays were applied to the volatile and polar fractions of peels and to crude and polar fraction of juices: 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging capacity, reducing power and inhibition of lipid peroxidation using beta-carotene-linoleate model system in liposomes and thiobarbituric acid reactive substances (TBARS) assay in brain homogenates. Reducing sugars and phenolics were the main antioxidant compounds found in all the extracts. Peels polar fractions revealed the highest contents in phenolics, flavonoids, ascorbic acid, carotenoids and reducing sugars, which certainly contribute to the highest antioxidant potential found in these fractions. Peels volatile fractions were clearly separated using discriminant analysis, which is in agreement with their lowest antioxidant potential. Copyright 2009 Elsevier Ltd. All rights reserved.

Indirect potentiometric titration of ascorbic acid in pharmaceutical preparations using copper based mercury film electrode.

PubMed

Abdul Kamal Nazer, Meeran Mohideen; Hameed, Abdul Rahman Shahul; Riyazuddin, Patel

2004-01-01

A simple and rapid potentiometric method for the estimation of ascorbic acid in pharmaceutical dosage forms has been developed. The method is based on treating ascorbic acid with iodine and titration of the iodide produced equivalent to ascorbic acid with silver nitrate using Copper Based Mercury Film Electrode (CBMFE) as an indicator electrode. Interference study was carried to check possible interference of usual excipients and other vitamins. The precision and accuracy of the method was assessed by the application of lack-of-fit test and other statistical methods. The results of the proposed method and British Pharmacopoeia method were compared using F and t-statistical tests of significance.

Effect of 3-methylcholanthrene-induced increases in ascorbic acid levels on tissue. beta. -glucuronidase activity in rats

DOE Office of Scientific and Technical Information (OSTI.GOV)

Calabrese, E.J.; Barrett, T.J.; Leonard, D.A.

1988-01-01

The interrelationship between tissue ascorbic acid levels and tissue ..beta..-glucuronidase activity was examined in rats injected with 3-methylcholanthrene, an agent which induces ascorbic acid synthesis in rats. Six Fisher 344 rats were dosed intraperitoneally (IP) with 30 mg/kg of 3-methylcholanthrene. Ascorbic acid levels and ..beta..-glucuronidase (..beta..-G) activity were determined for lung, liver and kidney tissues. In a follow-up study, rats were dosed for three consecutive days with 3-methylcholanthrene. Controls in both groups were dosed IP with Emulphor (EL-620). Animals were sacrificed one week after the final dosage and lung, liver and kidney tissues were examined.

Urinary and plasma oxalate during ingestion of pure ascorbic acid: a re-evaluation.

PubMed

Fituri, N; Allawi, N; Bentley, M; Costello, J

1983-01-01

Daily ingestion of 8 g of pure ascorbic acid by 8 normal subjects for 7 days did not, in contrast to previous reports in the literature, significantly alter urinary or plasma oxalate during or after ingestion. When urine with raised ascorbate values was heated at 100 degrees C for 30 min, a significant increase in urinary oxalate concentration was observed. Plasma ascorbate reached a mean value during ingestion of 3.3 mg/100 ml. Urinary citrate excretion significantly decreased during the first 4 days of ascorbic acid ingestion; however, the urinary inhibitory activity of calcium oxalate crystal growth was not significantly altered. Urinary and serum urate as well as urinary calcium and magnesium were unaltered by ingestion of the vitamin supplement.

Synthesis and antioxidant properties of a new lipophilic ascorbic acid analogue.

PubMed

Cotelle, Philippe; Cotelle, Nicole; Teissier, Elisabeth; Vezin, Hervé

2003-03-20

4-(4-Hydroxyphenyl)-5-(4-hydroxyphenylmethyl)-2-hydroxyfurane-2-one 1 was prepared by an acidic dimerisation of 4-hydroxyphenylpyruvic acid and some of its antioxidant and spectroscopic properties have been measured and compared to that of ascorbic acid. 1 is as good an antioxidant as ascorbic acid in the DPPH (2,2-diphenyl-1-picryl hydrazyl radical) test and the inhibition of hydroxyl radical and a powerful inhibitor of the Cu(2+) or AAPH (2,2'-azobis-(2-amidinopropane) dihydrochloride) induced oxidation of human LDL. 1 gives a stable radical characterised by its ESR spectrum similarly to ascorbic acid but in lower concentration and with a different reactivity towards nitroxides. Theoretical calculations allow us to propose the structure for the radical formed from 1, to explain its lower stability than ascorbyl radical and to evaluate the lipophilicity of 1.

Methemoglobinemia and ascorbate deficiency in hemoglobin E β thalassemia: metabolic and clinical implications

PubMed Central

Allen, Angela; Fisher, Christopher; Premawardhena, Anuja; Bandara, Dayananda; Perera, Ashok; Allen, Stephen; St Pierre, Timothy; Olivieri, Nancy

2012-01-01

During investigations of the phenotypic diversity of hemoglobin (Hb) E β thalassemia, a patient was encountered with persistently high levels of methemoglobin associated with a left-shift in the oxygen dissociation curve, profound ascorbate deficiency, and clinical features of scurvy; these abnormalities were corrected by treatment with vitamin C. Studies of erythropoietin production before and after treatment suggested that, as in an ascorbate-deficient murine model, the human hypoxia induction factor pathway is not totally dependent on ascorbate levels. A follow-up study of 45 patients with HbE β thalassemia showed that methemoglobin levels were significantly increased and that there was also a significant reduction in plasma ascorbate levels. Haptoglobin levels were significantly reduced, and the high frequency of the 2.2 haptoglobin genotype may place an additional pressure on ascorbate as a free-radical scavenger in this population. There was, in addition, a highly significant correlation between methemoglobin levels, splenectomy, and factors that modify the degree of globin-chain imbalance. Because methemoglobin levels are modified by several mechanisms and may play a role in both adaptation to anemia and vascular damage, there is a strong case for its further study in other forms of thalassemia and sickle-cell anemia, particularly when splenic function is defective. PMID:22885163

Hypolipidemic and antioxidative effects of aqueous enzymatic extract from rice bran in rats fed a high-fat and -cholesterol diet.

PubMed

Wang, Yu-Xin; Li, Yang; Sun, An-Min; Wang, Feng-Jiao; Yu, Guo-Ping

2014-09-16

The aqueous enzymatic extract from rice bran (AEERB) was rich in protein, γ-oryzanol and tocols. The aim of this study was to investigate the effects of AEERB on the regulation of lipid metabolism and the inhibition of oxidative damage. The antioxidant activity of AEERB in vitro was measured in terms of radical scavenging capacity, ferric reducing ability power (FRAP) and linoleic acid emulsion system-ferric thiocyanate method (FTC). Male Wistar rats were fed with a normal diet and a high-fat and high-cholesterol diet with or without AEERB. After treatment, biochemical assays of serum, liver and feces lipid levels, the antioxidant enzyme activity, malondialdehyde (MDA) and protein carbonyl were determined. AEERB is completely soluble in water and rich in hydrophilic and lipophilic functional ingredients. AEERB scavenged DPPH• and ABTS•+ and exhibited antioxidant activity slightly lower than that of ascorbic acid in the linoleic acid system. The administration of AEERB reduced serum lipid levels and the atherogenic index compared with those of the hyperlipidemic diet group (HD). The administration of AEERB significantly lowered liver lipid levels, inhibited hepatic 3-hydroxyl-3-methylglutaryl CoA reductase activity, and efficiently promoted the fecal excretion of total lipids and total cholesterol (TC) (p < 0.05). Dietary AEERB enhanced antioxidant status in the serum, liver and brain by increasing the antioxidant enzyme activity of superoxide dismutase (SOD), catalase (CAT), and glutathione peroxidase (GSH-Px) and decreasing the content of MDA and protein carbonyl. The results indicated that AEERB might act as a potent hypolipidemic and antioxidant functional food.

Effect of ascorbic acid on storage of Greyhound erythrocytes.

PubMed

Fontes, Jorge A; Banerjee, Uddyalok; Iazbik, M Cristina; Marín, Liliana M; Couto, C Guillermo; Palmer, Andre F

2015-09-01

To assess changes in biochemical and biophysical properties of canine RBCs during cold (1° to 6°C) storage in a licensed RBC additive solution (the RBC preservation solution designated AS-1) supplemented with ascorbic acid. Blood samples from 7 neutered male Greyhounds; all dogs had negative results when tested for dog erythrocyte antigen 1.1. Blood was collected into citrate-phosphate-dextrose and stored in AS-1. Stored RBCs were supplemented with 7.1mM ascorbic acid or with saline (0.9% NaCl) solution (control samples). Several biochemical and biophysical properties of RBCs were measured, including percentage hemolysis, oxygen-hemoglobin equilibrium, and the kinetic rate constants for O2 dissociation, carbon monoxide association, and nitric oxide dioxygenation. Greyhound RBCs stored in AS-1 supplemented with ascorbic acid did not have significantly decreased hemolysis, compared with results for the control samples, during the storage period. In this study, ascorbic acid did not reduce hemolysis during storage. Several changes in stored canine RBCs were identified as part of the hypothermic storage lesion.

Development of smart delivery system for ascorbic acid using pH-responsive P(MAA-co-EGMA) hydrogel microparticles.

PubMed

Lee, Eunmi; Kim, Kyusik; Choi, Moonjae; Lee, Youngmoo; Park, Jin-Won; Kim, Bumsang

2010-11-01

pH-Responsive P(MAA-co-EGMA) hydrogel microparticles were prepared and their feasibility as intelligent delivery carriers was evaluated. P(MAA-co-EGMA) hydrogel microparticles were synthesized via dispersion photopolymerization. There was a drastic change in the swelling ratio of P(MAA-co-EGMA) microparticles at a pH of ~ 5 and, as the amount of MAA in the hydrogel increased, the swelling ratio increased at a pH above 5. The loading efficiency of the ascorbic acid into the hydrogel was affected more by the degree of swelling of the hydrogel than the electrostatic interaction between the hydrogel and the loaded ascorbic acid. The P(MAA-co-EGMA) hydrogel microparticles showed a pH-sensitive release behavior. Thus, at pH 4 almost none of the ascorbic acid permeated through the skin while at pH 6 relatively high skin permeability was obtained. The ascorbic acid loaded in the hydrogel particles was hardly degraded and its stability was maintained at high temperature.

Beyond the redox imbalance: oxidative stress contributes to an impaired GLUT3 modulation in Huntington's disease

PubMed Central

Covarrubias-Pinto, Adriana; Moll, Pablo; Solís-Maldonado, Macarena; Acuña, Aníbal I.; Riveros, Andrea; Miró, María Paz; Papic, Eduardo; Beltrán, Felipe A.; Cepeda, Carlos; Concha, Ilona I.; Brauchi, Sebastián; Castro, Maite A.

2016-01-01

Failure in energy metabolism and oxidative damage are associated with Huntington’s disease (HD). Ascorbic acid released during synaptic activity inhibits use of neuronal glucose, favouring lactate uptake to sustain brain activity. Here, we observe a decreased expression of GLUT3 in STHdhQ111 cells (HD cells) and R6/2 mice (HD mice). Localisation of GLUT3 is decreased at the plasma membrane in HD cells affecting the modulation of glucose uptake by ascorbic acid. An ascorbic acid analogue without antioxidant activity is able to inhibit glucose uptake in HD cells. The impaired modulation of glucose uptake by ascorbic acid is directly related to ROS levels indicating that oxidative stress sequesters the ability of ascorbic acid to modulate glucose utilisation. Therefore, in HD, a decrease in GLUT3 localisation at the plasma membrane would contribute to an altered neuronal glucose uptake during resting periods while redox imbalance should contribute to metabolic failure during synaptic activity. PMID:26456058

Evaluation of non-thermal effects of electricity on ascorbic acid and carotenoid degradation in acerola pulp during ohmic heating.

PubMed

Jaeschke, Débora Pez; Marczak, Ligia Damasceno Ferreira; Mercali, Giovana Domeneghini

2016-05-15

The effect of electric field on ascorbic acid and carotenoid degradation in acerola pulp during ohmic heating was evaluated. Ascorbic acid kinetic degradation was evaluated at 80, 85, 90 and 95°C during 60 min of thermal treatment by ohmic and conventional heating. Carotenoid degradation was evaluated at 90 and 95°C after 50 min of treatment. The different temperatures evaluated showed the same effect on degradation rates. To investigate the influence of oxygen concentration on the degradation process, ohmic heating was also carried out under rich and poor oxygen modified atmospheres at 90°C. Ascorbic acid and carotenoid degradation was higher under a rich oxygen atmosphere, indicating that oxygen is the limiting reagent of the degradation reaction. Ascorbic acid and carotenoid degradation was similar for both heating technologies, demonstrating that the presence of the oscillating electric field did not influence the mechanisms and rates of reactions associated with the degradation process. Copyright © 2015 Elsevier Ltd. All rights reserved.

Gender difference following high cholesterol diet induced renal injury and the protective role of rutin and ascorbic acid combination in Wistar albino rats

PubMed Central

2012-01-01

Background An increased interest is given to the impact of high fat diet on health worldwide. Abnormalities in lipid metabolism induced by high cholesterol diet (HCD) were reported to exacerbate renal diseases via oxidative stress pathways. Rutin and ascorbic acid showed a protective role against oxidative stress-mediated diseases. Furthermore, both lipid metabolism and tissue response to oxidative stress damage was found to vary according to animal gender. Thus, the objective of this work was to examine possible gender-related differences and the possible protective effects of rutin and ascorbic acid supplementation on high cholesterol diet induced nephrotoxicity. Methods 96 young male and female Wistar albino rats were used. HCD supplemented animals were treated with rutin alone or in combination with ascorbic acid for 6 weeks. Creatinine plasma level was estimated. Furthermore, kidney levels of nucleic acids, total protein, malondialdehyde (MDA), reduced glutathione (GSH), total cholesterol, and triglycerides were determined. Finally, kidney tissues were used for histopathological examination. Results HCD supplementation decreased kidney level of nucleic acids, which was more prominent in female animals. Both vitamin combination significantly attenuated HCD induced decrease in nucleic acids. Moreover, kidney level of MDA was significantly altered by HCD in both genders, which was inhibited by rutin and ascorbic acid alone or in combination in male groups and by both vitamins in female groups. There was a reduction in kidney level of GSH by HCD, especially in male groups, which was attenuated by rutin and ascorbic acid combination. Kidney levels of total cholesterol and triglycerides were significantly increased by HCD supplementation in both genders. Coadministration with rutin and/or ascorbic acid protected from such increase, which was more obvious in both vitamins combination. Histopathological investigation supported vitamins protective effect, which was more prominent in male vitamins combination group. Conclusions HCD-induced renal injury in female was higher than in male animals, suggesting a better anti-oxidative stress defense response in male's kidney. Moreover, the antioxidant and reno-protective effects of rutin and ascorbic acid were augmented following their combination. PMID:22423898

Gender difference following high cholesterol diet induced renal injury and the protective role of rutin and ascorbic acid combination in Wistar albino rats.

PubMed

Al-Rejaie, Salim Salih; Abuohashish, Hatem Mustafa; Alkhamees, Osama Abdelrahman; Aleisa, Abdulaziz Mohammed; Alroujayee, Abdulaziz S

2012-03-16

An increased interest is given to the impact of high fat diet on health worldwide. Abnormalities in lipid metabolism induced by high cholesterol diet (HCD) were reported to exacerbate renal diseases via oxidative stress pathways. Rutin and ascorbic acid showed a protective role against oxidative stress-mediated diseases. Furthermore, both lipid metabolism and tissue response to oxidative stress damage was found to vary according to animal gender. Thus, the objective of this work was to examine possible gender-related differences and the possible protective effects of rutin and ascorbic acid supplementation on high cholesterol diet induced nephrotoxicity. 96 young male and female Wistar albino rats were used. HCD supplemented animals were treated with rutin alone or in combination with ascorbic acid for 6 weeks. Creatinine plasma level was estimated. Furthermore, kidney levels of nucleic acids, total protein, malondialdehyde (MDA), reduced glutathione (GSH), total cholesterol, and triglycerides were determined. Finally, kidney tissues were used for histopathological examination. HCD supplementation decreased kidney level of nucleic acids, which was more prominent in female animals. Both vitamin combination significantly attenuated HCD induced decrease in nucleic acids. Moreover, kidney level of MDA was significantly altered by HCD in both genders, which was inhibited by rutin and ascorbic acid alone or in combination in male groups and by both vitamins in female groups. There was a reduction in kidney level of GSH by HCD, especially in male groups, which was attenuated by rutin and ascorbic acid combination. Kidney levels of total cholesterol and triglycerides were significantly increased by HCD supplementation in both genders. Coadministration with rutin and/or ascorbic acid protected from such increase, which was more obvious in both vitamins combination. Histopathological investigation supported vitamins protective effect, which was more prominent in male vitamins combination group. HCD-induced renal injury in female was higher than in male animals, suggesting a better anti-oxidative stress defense response in male's kidney. Moreover, the antioxidant and reno-protective effects of rutin and ascorbic acid were augmented following their combination.

Optimization of Supercritical Fluid Extraction of Total Alkaloids, Peimisine, Peimine and Peiminine from the Bulb of Fritillaria thunbergii Miq, and Evaluation of Antioxidant Activities of the Extracts

PubMed Central

Ruan, Xiao; Yang, Li; Cui, Wen-Xia; Zhang, Men-Xing; Li, Zhao-Hui; Liu, Ben; Wang, Qiang

2016-01-01

Supercritical fluid extraction (SFE) was used to extract total alkaloids, peimisine, peimine and peiminine from the bulb of Fritillaria thunbergii Miq. The antioxidant capacity of the extracts was evaluated by DPPH radical scavenging activity (DPPH-RSA), ABTS radical scavenging activity (ABTS-RSA) and ferric reducing capacity (FRAP) assay. A central composite design (CCD) with four variables and five levels was employed for optimization of process parameters, and response surface plots were constructed in accordance with a second order polynomial model. Under optimal conditions of 3.0 h, 60.4 °C, 26.5 MPa and 89.3% ethanol, the highest yields were predicted to be 3.8 mg/g for total alkaloids, 0.5 mg/g for peimisine, 1.3 mg/g for peimine and 1.3 mg/g for peiminine, and the antioxidant capacity of extracts displayed EC50, DPPH value of 5.5 mg/mL, EC50, ABTS value of 0.3 mg/mL and FRAP value of 118.2 mg ascorbic acid equivalent (AAE)/100 g. PMID:28773648

Antioxidant Properties and Cardioprotective Mechanism of Malaysian Propolis in Rats.

PubMed

Ahmed, Romana; Tanvir, E M; Hossen, Md Sakib; Afroz, Rizwana; Ahmmed, Istiyak; Rumpa, Nur-E-Noushin; Paul, Sudip; Gan, Siew Hua; Sulaiman, Siti Amrah; Khalil, Md Ibrahim

2017-01-01

Propolis contains high concentrations of polyphenols, flavonoids, tannins, ascorbic acid, and reducing sugars and proteins. Malaysian Propolis (MP) has been reported to exhibit high 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical-scavenging activity and ferric reducing antioxidant power (FRAP) values. Herein, we report the antioxidant properties and cardioprotective properties of MP in isoproterenol- (ISO-) induced myocardial infarction in rats. Male Wistar rats ( n = 32) were pretreated orally with an ethanol extract of MP (100 mg/kg/day) for 30 consecutive days. Subcutaneous injection of ISO (85 mg/kg in saline) for two consecutive days caused a significant increase in serum cardiac marker enzymes and cardiac troponin I levels and altered serum lipid profiles. In addition significantly increased lipid peroxides and decreased activities of cellular antioxidant defense enzymes were observed in the myocardium. However, pretreatment of ischemic rats with MP ameliorated the biochemical parameters, indicating the protective effect of MP against ISO-induced ischemia in rats. Histopathological findings obtained for the myocardium further confirmed the biochemical findings. It is concluded that MP exhibits cardioprotective activity against ISO-induced oxidative stress through its direct cytotoxic radical-scavenging activities. It is also plausible that MP contributed to endogenous antioxidant enzyme activity via inhibition of lipid peroxidation.

Antioxidant properties and inhibitory effects of Satureja khozestanica essential oil on LDL oxidation induced-CuSO4 in vitro

PubMed Central

Bagheri, Shahrokh; Ahmadvand, Hassan; Khosrowbeygi, Ali; Ghazanfari, Farshid; Jafari, Narges; Nazem, Habibolah; Hosseini, Reza Haji

2013-01-01

Objective To assess various antioxidative activities of Satureja khozestanica essential oil (SKE) and its effect on oxidation of low density lipoprotein (LDL) induced by CuSO4 in vitro by monitoring the formation of conjugated dienes and malondialdehyde (MDA). Methods The formation of conjugated dienes, lag time and MDA were measured. Inhibition of this Cu-induced oxidation was studied in the presence of several concentrations of SKE. Also total antioxidant activity and free radical scavenging of SKE were determinated. Results It was demonstrated that SKE was able to inhibit LDL oxidation and decrease the resistance of LDL against oxidation. The inhibitory effects of SKE on LDL oxidation were dose-dependent at concentrations ranging from 50 to 200 µg/mL. Total antioxidant capacity of SKE was (3.20±0.40) nmol of ascorbic acid equivalents/g SKE. The SKE showed remarkable scavenging activity on 2, 2-diphenyl-picrylhydrazyl, IC50 (5.30±0.11) ng/mL. Conclusions This study shows that SKE is a source of potent antioxidants and prevents the oxidation of LDL in vitro and it may be suitable for use in food and pharmaceutical applications. PMID:23570012

Sodium Bicarbonate-Ascorbic Acid Combination for Prevention of Contrast-Induced Nephropathy in Chronic Kidney Disease Patients Undergoing Catheterization.

PubMed

Komiyama, Kota; Ashikaga, Takashi; Inagaki, Dai; Miyabe, Tomonori; Arai, Marina; Yoshida, Kiyotaka; Miyazawa, Satoshi; Nakada, Akihiro; Kawamura, Iwanari; Masuda, Shinichiro; Nagamine, Sho; Hojo, Rintaro; Aoyama, Yuya; Tsuchiyama, Takaaki; Fukamizu, Seiji; Shibui, Takashi; Sakurada, Harumizu

2017-01-25

Sodium bicarbonate and ascorbic acid have been proposed to prevent contrast-induced nephropathy (CIN). The present study evaluated the effect of their combined use on CIN incidence.Methods and Results:We prospectively enrolled 429 patients with chronic kidney disease (CKD: baseline estimated glomerular filtration rate <60 mL/min/1.73 m 2 ) prior to elective coronary catheterization. CIN was defined as absolute (≥0.5 mg/dL) or relative (≥25%) increase in serum creatinine within 72 h. In the saline hydration (n=218) and combined sodium bicarbonate+ascorbic acid (n=211) groups, a total of 1,500-2,500 mL 0.9% saline was given before and after the procedure. In addition, the combination group received 20 mEq sodium bicarbonate and 3 g ascorbic acid i.v. before the procedure, followed by 2 g ascorbic acid after the procedure and a further 2 g after 12 h. There were no significant differences between the basic characteristics and contrast volume in the 2 groups. CIN occurred in 19 patients (8.7%) in the saline group, and in 6 patients (2.8%) in the combined treatment group (P=0.008). Combined sodium bicarbonate and ascorbic acid could prevent CIN following catheterization in CKD patients.

Synthesis of colloidal silver nanoparticle clusters and their application in ascorbic acid detection by SERS.

PubMed

Cholula-Díaz, Jorge L; Lomelí-Marroquín, Diana; Pramanick, Bidhan; Nieto-Argüello, Alfonso; Cantú-Castillo, Luis A; Hwang, Hyundoo

2018-03-01

Ascorbic acid (vitamin C) has an essential role in the human body mainly due to its antioxidant function. In this work, metallic silver nanoparticle (AgNP) colloids were used in SERS experiments to detect ascorbic acid in aqueous solution. The AgNPs were synthesized by a green method using potato starch as reducing and stabilizing agent, and water as the solvent. The optical properties of the yellowish as-synthesized silver colloids were characterized by UV-vis spectroscopy, in which besides a typical band at 410 nm related to the localized surface plasmon resonance of the silver nanoparticles, a shoulder band around 500 nm, due to silver nanoparticle cluster formation, is presented when relatively higher concentrations of starch are used in the synthesis. These starch-capped silver nanoparticles show an intrinsic Raman peak at 1386 cm -1 assigned to deformation modes of the starch structure. The increase of the intensity of the SERS peak at 1386 cm -1 with an increase in the concentration of the ascorbic acid is related to a decrease of the gap between dimers and trimers of the silver nanoparticle clusters produced by the presence of ascorbic acid in the colloid. The limit of detection of this technique for ascorbic acid is 0.02 mM with a measurement concentration range of 0.02-10 mM, which is relevant for the application of this method for detecting ascorbic acid in biological specimen. Copyright © 2017 Elsevier B.V. All rights reserved.

Cryptosporidium-contaminated water disinfection by a novel Fenton process.

PubMed

Matavos-Aramyan, Sina; Moussavi, Mohsen; Matavos-Aramyan, Hedieh; Roozkhosh, Sara

2017-05-01

Three novel modified advanced oxidation process systems including ascorbic acid-, pro-oxidants- and ascorbic acid-pro-oxidants-modified Fenton system were utilized to study the disinfection efficiency on Cryptosporidium-contaminated drinking water samples. Different concentrations of divalent and trivalent iron ions, hydrogen peroxide, ascorbic acid and pro-oxidants at different exposure times were investigated. These novel systems were also compared to the classic Fenton system and to the control system which comprised of only hydrogen peroxide. The complete in vitro mechanism of the mentioned modified Fenton systems are also provided. The results pointed out that by considering the optimal parameter limitations, the ascorbic acid-modified Fenton system decreased the Cryptosporidium oocytes viability to 3.91%, while the pro-oxidant-modified and ascorbic acid-pro-oxidant-modified Fenton system achieved an oocytes viability equal to 1.66% and 0%, respectively. The efficiency of the classic Fenton at optimal condition was observed to be 20.12% of oocytes viability. The control system achieved 86.14% of oocytes viability. The optimum values of the operational parameters during this study are found to be 80mgL -1 for the divalent iron, 30mgL -1 for ascorbic acid, 30mmol for hydrogen peroxide, 25mgL -1 for pro-oxidants and an exposure time equal to 5min. The ascorbic acid-pro-oxidants-modified Fenton system achieved a promising complete water disinfection (0% viability) at the optimal conditions, leaving this method a feasible process for water disinfection or decontamination, even at industrial scales. Copyright © 2017 Elsevier Inc. All rights reserved.

Ascorbic acid prevents vascular dysfunction induced by oral glucose load in healthy subjects.

PubMed

De Marchi, Sergio; Prior, Manlio; Rigoni, Anna; Zecchetto, Sara; Rulfo, Fanny; Arosio, Enrico

2012-01-01

To examine the effects of oral glucose load on forearm circulatory regulation before and after ascorbic acid administration in healthy subjects. Microcirculation study with laser Doppler was performed at the hand in basal conditions, after ischemia and after acetylcholine and nitroprusside; strain gauge plethysmography was performed at basal and after ischemia. The tests were repeated in the same sequence 2 hour after oral administration of glucose (75 g). The subjects were randomised for administration of ascorbic acid (1 g bid) or placebo (sodium bicarbonate 1 g bid) for 10 days. After that, the tests were repeated before and after a new oral glucose load. Blood pressure and heart rate were monitored. Macrocirculatory flux, pressure values and heart rate were unvaried throughout the study. The glucose load caused a reduction in the hyperemic peak flow with laser Doppler and plethysmography; it reduced flux recovery time and hyperemic curve area after ischemia; acetylcholine elicited a minor increase in flux with laser Doppler. The response to nitroprusside was unvaried after glucose load as compared to basal conditions. Treatment with ascorbic acid prevented the decrease in hyperemia after glucose, detected with laser Doppler and plethysmography. Ascorbic acid prevented the decreased response to acetylcholine after glucose, the response to nitroprusside was unaffected by ascorbic acid. Results after placebo were unvaried. Oral glucose load impairs endothelium dependent dilation and hyperaemia at microcirculation, probably via oxidative stress; ascorbic acid can prevent it. Copyright © 2011 European Federation of Internal Medicine. Published by Elsevier B.V. All rights reserved.

Oxidative stress in the hippocampus during experimental seizures can be ameliorated with the antioxidant ascorbic acid

PubMed Central

Santos, Ítala Mônica Sales; da Rocha Tomé, Adriana; Saldanha, Gláucio Barros; Ferreira, Paulo Michel Pinheiro; Militão, Gardenia Carmem Gadelha

2009-01-01

Ascorbic acid has many nonenzymatic actions and is a powerful water-soluble antioxidant. It protects low density lipoproteins from oxidation and reduces harmful oxidants in the central nervous system. Pilocarpine-induced seizures have been suggested to be mediated by increases in oxidative stress. Current studies have suggested that antioxidant compounds may afford some level of neuroprotection against the neurotoxicity of seizures. The objective of the present study was to evaluate the neuroprotective effects of ascorbic acid (AA) in rats, against the observed oxidative stress during seizures induced by pilocarpine. Wistar rats were treated with 0.9% saline (i.p., control group), ascorbic acid (500 mg/kg, i.p., AA group), pilocarpine (400 mg/kg, i.p., pilocarpine group), and the association of ascorbic acid (500 mg/kg, i.p.) plus pilocarpine (400 mg/kg, i.p.), 30 min before of administration of ascorbic acid (AA plus pilocarpine group). After the treatments all groups were observed for 6 h. The enzyme activities as well as the lipid peroxidation and nitrite concentrations were measured using spectrophotometric methods and the results compared to values obtained from saline and pilocarpine-treated animals. Protective effects of ascorbic acid were also evaluated on the same parameters. In pilocarpine group there was a significant increase in lipid peroxidation and nitrite level. However, no alteration was observed in superoxide dismutase and catalase activities. Antioxidant treatment significantly reduced the lipid peroxidation level and nitrite content as well as increased the superoxide dismutase and catalase activities in hippocampus of adult rats after seizures induced by pilocarpine. Our findings strongly support the hypothesis that oxidative stress in hippocampus occurs during seizures induced by pilocarpine, proving that brain damage induced by the oxidative process plays a crucial role in seizures pathogenic consequences, and also imply that a strong protective effect could be achieved using ascorbic acid. PMID:20716907

Inhibition of free radical-induced erythrocyte hemolysis by 2-O-substituted ascorbic acid derivatives.

PubMed

Takebayashi, Jun; Kaji, Hiroaki; Ichiyama, Kenji; Makino, Kazutaka; Gohda, Eiichi; Yamamoto, Itaru; Tai, Akihiro

2007-10-15

Inhibitory effects of 2-O-substituted ascorbic acid derivatives, ascorbic acid 2-glucoside (AA-2G), ascorbic acid 2-phosphate (AA-2P), and ascorbic acid 2-sulfate (AA-2S), on 2,2'-azobis(2-amidinopropane) dihydrochloride (AAPH)-induced oxidative hemolysis of sheep erythrocytes were studied and were compared with those of ascorbic acid (AA) and other antioxidants. The order of the inhibition efficiency was AA-2S> or =Trolox=uric acid> or =AA-2P> or =AA-2G=AA>glutathione. Although the reactivity of the AA derivatives against AAPH-derived peroxyl radical (ROO(*)) was much lower than that of AA, the derivatives exerted equal or more potent protective effects on AAPH-induced hemolysis and membrane protein oxidation. In addition, the AA derivatives were found to react per se with ROO(*), not via AA as an intermediate. These findings suggest that secondary reactions between the AA derivative radical and ROO(*) play a part in hemolysis inhibition. Delayed addition of the AA derivatives after AAPH-induced oxidation of erythrocytes had already proceeded showed weaker inhibition of hemolysis compared to that of AA. These results suggest that the AA derivatives per se act as biologically effective antioxidants under moderate oxidative stress and that AA-2G and AA-2P may be able to act under severe oxidative stress after enzymatic conversion to AA in vivo.

In vitro antioxidant capacity and free radical scavenging evaluation of active metabolite constituents of Newbouldia laevis ethanolic leaf extract.

PubMed

Habu, Josiah Bitrus; Ibeh, Bartholomew Okechukwu

2015-03-14

The aim of the present study was to evaluate the in vitro antioxidant and free radical scavenging capacity of bioactive metabolites present in Newbouldia laevis leaf extract. Chromatographic and spectrophotometric methods were used in the study and modified where necessary in the study. Bioactivity of the extract was determined at 10 μg/ml, 50 μg/ml, 100 μg/ml, 200 μg/ml and 400 μg/ml concentrations expressed in % inhibition. The yield of the ethanolic leaf extract of N.laevis was 30.3 g (9.93%). Evaluation of bioactive metabolic constituents gave high levels of ascorbic acid (515.53 ± 12 IU/100 g [25.7 mg/100 g]), vitamin E (26.46 ± 1.08 IU/100 g), saponins (6.2 ± 0.10), alkaloids (2.20 ± 0.03), cardiac glycosides(1.48 ± 0.22), amino acids and steroids (8.01 ± 0.04) measured in mg/100 g dry weight; moderate levels of vitamin A (188.28 ± 6.19 IU/100 g), tannins (0.09 ± 0.30), terpenoids (3.42 ± 0.67); low level of flavonoids (1.01 ± 0.34 mg/100 g) and absence of cyanogenic glycosides, carboxylic acids and aldehydes/ketones. The extracts percentage inhibition of DPPH, hydroxyl radical (OH.), superoxide anion (O2 .-), iron chelating, nitric oxide radical (NO), peroxynitrite (ONOO-), singlet oxygen (1O2), hypochlorous acid (HOCl), lipid peroxidation (LPO) and FRAP showed a concentration-dependent antioxidant activity with no significant difference with the controls. Though, IC50 of the extract showed significant difference only in singlet oxygen (1O2) and iron chelating activity when compared with the controls. The extract is a potential source of antioxidants/free radical scavengers having important metabolites which maybe linked to its ethno-medicinal use.

Microencapsulation of methylglyoxal and two derivatives

NASA Technical Reports Server (NTRS)

Nozawa, Y.; Fox, S. W.

1981-01-01

Microcapsules of methylglyoxal, methylglyoxal bis(guanylhydrazone), and methylglyoxal-ascorbic acid condensation complex were prepared and release curves were determined. The effect of various concentrations of hydrochloric acid on the decomposition of the ascorbic acid complex was investigated.

Reversal of alcohol induced testicular hyperlipidemia by supplementation of ascorbic acid and its comparison with abstention in male guinea pigs.

PubMed

Radhakrishnakartha, Harikrishnan; Appu, Abhilash Puthuvelvippel; Madambath, Indira

2014-02-01

Chronic ethanol exposure causes hyperlipidemia. The present study was designed to investigate the impact of ascorbic acid supplementation on ethanol induced hyperlipidemia in testis and to compare it with that of abstinence from taking alcohol. Thirty-six male guinea pigs were divided into two groups and were maintained for 90 days as follows (1) control (C) (2) ethanol treated group (E) (4 g/kg body wt/day). Ethanol was administered for 90 days and on 90th day, alanine amino transaminase (ALT), aspartate amino transaminase (AST) and γ-glutamyltransferase (GGT) in serum was assayed. The animals in the ethanol group were further divided into an ascorbic acid supplemented group (25 mg/100 g body wt/day) (E+AA) and an ethanol abstention group (EAG) and those in the control group were divided into a control group and a control+ascorbic acid group (C+AA). There was significant increase in levels of testicular cholesterol, free fatty acid, phospholipids and triglycerides in the ethanol group. There was also a significant increase in the activity of HMG CoA reductase and decrease in activity of testicular glucose-6-phosphate dehydrogenase (G6PDH) and malic enzyme in ethanol-ingested animals that further led to decreased levels of serum testosterone. Alcohol administration also enhanced the activity of testicular alcohol dehydrogenase (ADH). Ascorbic acid supplementation and abstention altered all these parameters induced by chronic alcohol administration. Histological studies were also in line with the above results. Ascorbic acid was able to reinstate the cholesterol homeostasis in testis which could have further restored the testicular steroidogenesis. The present study demonstrated that ascorbic acid is effective in reducing the hyperlipidemia induced by chronic alcohol administration and produced a better recovery than abstention.

Local indigenous fruit-derived juices as alternate source of acidity regulators.

PubMed

D'souza, Cassandra; Fernandes, Rosaline; Kudale, Subhash; Naik, Azza Silotry

2018-03-01

Acidity regulators are additives that alter and control food acidity. The objective of this study was to explore local indigenous fruits as sources of natural acidity regulators. Juices extracted from Garcinia indica (kokum), Embilica officinalis (amla) and Tamarindus indica (tamarind) were used as acidulants for media such as coconut milk and bottle gourd juice. The buffering capacity β, acid composition, antioxidant activity and shelf-life study of the acidified media were estimated. Potentiometric titration showed G. indica to possess the highest buffering capacity in both ranges. High-performance liquid chromatography analysis showed T. indica contained a high level of tartaric acid (4.84 ± 0.01 mg g -1 ), while G. indica had citric acid (22.37 ± 0.84 mg g -1 ) and E. officinalis had citric acid (2.75 ± 0.02 mg g -1 ) along with ascorbic acid (2.68 ± 0.01 mg g -1 ). 1,1-Diphenyl-2-picrylhydrazyl scavenging activity was high for E. officinalis (91.24 ± 0.66%) and T. indica (90.93 ± 0.817%) and relatively lower for G. indica (34.61 ± 3.66%). The shelf-life study showed total plate count to be within the prescribed limits up to a week, in accordance with safety regulations. This investigation confirmed the suitability of indigenous fruit juices as alternatives to existing acidity regulators. © 2017 Society of Chemical Industry. © 2017 Society of Chemical Industry.

Screening of the antioxidative properties and total phenolic contents of three endemic Tanacetum subspecies from Turkish flora.

PubMed

Tepe, Bektas; Sokmen, Atalay

2007-11-01

Methanolic extracts of three different Tanacetum subspecies [Tanacetum densum (Lab.) Schultz Bip. subsp. sivasicum Hub-Mor and Grierson, Tanacetum densum (Lab.) Schultz Bip. subsp. eginense Heywood and Tanacetum densum (Lab.) Schultz Bip. subsp. amani Heywood] which are endemic to Turkish flora were screened for their possible antioxidant activities by two complementary test systems namely DPPH free radical scavenging and beta-carotene/linoleic acid. In DPPH system, the most active plant was T. densum subsp. amani with an IC(50) value of 69.30+/-0.37 microg/ml. On the other hand, T. densum subsp. sivasicum exerted greater antioxidant activity than those of other subspecies in beta-carotene/linoleic acid system (79.10%+/-1.83). Antioxidant activities of BHT, curcumine and ascorbic acid were also determined as positive controls in parallel experiments. Total phenolic constituents of the extracts of Tanacetum subspecies were performed employing the literature methods involving Folin-Ciocalteu reagent and gallic acid as standard. The amount of total phenolics was highest in subsp. sivasicum (162.33+/-3.57 microg/mg), followed by subsp. amani (158.44+/-2.17 microg/mg). Especially, a positive correlation was observed between total phenolic content and antioxidant activity of the extracts.

Reduction of the DNA damages, Hepatoprotective Effect and Antioxidant Potential of the Coconut Water, ascorbic and Caffeic Acids in Oxidative Stress Mediated by Ethanol.

PubMed

Bispo, Vanderson S; Dantas, Lucas S; Chaves, Adriano B; Pinto, Isabella F D; Silva, Railmara P DA; Otsuka, Felipe A M; Santos, Rodrigo B; Santos, Aline C; Trindade, Danielle J; Matos, Humberto R

2017-01-01

Hepatic disorders such as steatosis and alcoholic steatohepatitis are common diseases that affect thousands of people around the globe. This study aims to identify the main phenol compounds using a new HPLC-ESI+-MS/MS method, to evaluate some oxidative stress parameters and the hepatoprotective action of green dwarf coconut water, caffeic and ascorbic acids on the liver and serum of rats treated with ethanol. The results showed five polyphenols in the lyophilized coconut water spiked with standards: chlorogenic acid (0.18 µM), caffeic acid (1.1 µM), methyl caffeate (0.03 µM), quercetin (0.08 µM) and ferulic acid (0.02 µM) isomers. In the animals, the activity of the serum γ-glutamyltranspeptidase (γ-GT) was reduced to 1.8 I.U/L in the coconut water group, 3.6 I.U/L in the ascorbic acid group and 2.9 I.U/L in the caffeic acid groups, when compared with the ethanol group (5.1 I.U/L, p<0.05). Still in liver, the DNA analysis demonstrated a decrease of oxidized bases compared to ethanol group of 36.2% and 48.0% for pretreated and post treated coconut water group respectively, 42.5% for the caffeic acid group, and 34.5% for the ascorbic acid group. The ascorbic acid was efficient in inhibiting the thiobarbituric acid reactive substances (TBARS) in the liver by 16.5% in comparison with the ethanol group. These data indicate that the green dwarf coconut water, caffeic and ascorbic acids have antioxidant, hepatoprotective and reduced DNA damage properties, thus decreasing the oxidative stress induced by ethanol metabolism.

Oxalate deposition on asbestos bodies.

PubMed

Ghio, Andrew J; Roggli, Victor L; Richards, Judy H; Crissman, Kay M; Stonehuerner, Jacqueline D; Piantadosi, Claude A

2003-08-01

We report on a deposition of oxalate crystals on ferruginous bodies after occupational exposure to asbestos demonstrated in 3 patients. We investigated the mechanism and possible significance of this deposition by testing the hypothesis that oxalate generated through nonenzymatic oxidation of ascorbate by asbestos-associated iron accounts for the deposition of the crystal on a ferruginous body. Crocidolite asbestos (1000 microg/mL) was incubated with 500 micromol H(2)O(2) and 500 micromol ascorbate for 24 hours at 22 degrees C. The dependence of oxalate generation on iron-catalyzed oxidant production was tested with the both the metal chelator deferoxamine and the radical scavenger dimethylthiourea. Incubation of crocidolite, H(2)O(2), and ascorbate in vitro generated approximately 42 nmol of oxalate in 24 hours. Oxalate generation was diminished significantly by the inclusion of either deferoxamine or dimethylthiourea in the reaction mixture. Incubation of asbestos bodies and uncoated fibers isolated from human lung with 500 micromol H(2)O(2) and 500 micromol ascorbate for 24 hours at 22 degrees C resulted in the generation of numerous oxalate crystals. We conclude that iron-catalyzed production of oxalate from ascorbate can account for the deposition of this crystal on ferruginous bodies.

Comparing the moisturizing effects of ascorbic acid and calcium ascorbate against that of tocopherol in emulsions.

PubMed

Gönüllü, U; Sensoy, D; Uner, M; Yener, G; Altinkurt, T

2006-01-01

Calcium ascorbate (CAAS), which is a hydrophilic and stable derivative of ascorbic acid (vitamin C) (AA), is commonly used in foods as an antioxidative agent. There are very limited reports on its dermatological use in the literature. In this paper, it is reported that CAAS could be used in place of ascorbic acid, which has chemical stability problems in topicals due to degradation by oxidation. The aim of this study was to investigate the skin-hydrating effect of CAAS compared to those of ascorbic acid and tocopherol (vitamin E) (T), which is a potential skin moisturizer and commonly used in dermocosmetics. Vitamins are incorporated into two kinds of base creams (o/w and w/o emulsion creams), alone and in combinations. Formulations were applied to the inner forearms of volunteers, and skin conductance was measured by using a corneometer. Data obtained were statistically evaluated. It was found that the skin-hydrating effect of CAAS was higher than that of AA and lower than that of T. However, its effect was very close to that of T.

Characterization of the volatile composition of essential oils of some lamiaceae spices and the antimicrobial and antioxidant activities of the entire oils.

PubMed

Bozin, Biljana; Mimica-Dukic, Neda; Simin, Natasa; Anackov, Goran

2006-03-08

The essential oils of Ocimum basilicum L., Origanum vulgare L., and Thymus vulgaris L. were analyzed by means of gas chromatography-mass spectrometry and assayed for their antioxidant and antimicrobial activities. The antioxidant activity was evaluated as a free radical scavenging capacity (RSC), together with effects on lipid peroxidation (LP). RSC was assessed measuring the scavenging activity of the essential oils on 2,2-diphenyl-1-picrylhydrazil (DPPH(*)) and OH(*) radicals. Effects on LP were evaluated following the activities of essential oils in Fe(2+)/ascorbate and Fe(2+)/H(2)O(2) systems of induction. Essential oils exhibited very strong RSCs, reducing the DPPH radical formation (IC(50)) in the range from 0.17 (oregano) to 0.39 microg/mL (basil). The essential oil of T. vulgaris exhibited the highest OH radical scavenging activity, although none of the examined essential oils reached 50% of neutralization (IC(50)). All of the tested essential oils strongly inhibited LP, induced either by Fe(2+)/ascorbate or by Fe(2+)/H(2)O(2). The antimicrobial activity was tested against 13 bacterial strains and six fungi. The most effective antibacterial activity was expressed by the essential oil of oregano, even on multiresistant strains of Pseudomonas aeruginosa and Escherichia coli. A significant rate of antifungal activity of all of the examined essential oils was also exhibited.

Intravenous ascorbic acid to prevent and treat cancer-associated sepsis?

PubMed Central

2011-01-01

The history of ascorbic acid (AA) and cancer has been marked with controversy. Clinical studies evaluating AA in cancer outcome continue to the present day. However, the wealth of data suggesting that AA may be highly beneficial in addressing cancer-associated inflammation, particularly progression to systemic inflammatory response syndrome (SIRS) and multi organ failure (MOF), has been largely overlooked. Patients with advanced cancer are generally deficient in AA. Once these patients develop septic symptoms, a further decrease in ascorbic acid levels occurs. Given the known role of ascorbate in: a) maintaining endothelial and suppression of inflammatory markers; b) protection from sepsis in animal models; and c) direct antineoplastic effects, we propose the use of ascorbate as an adjuvant to existing modalities in the treatment and prevention of cancer-associated sepsis. PMID:21375761

Ascorbic Acid Efflux from Human Brain Microvascular Pericytes: Role of Re-uptake

PubMed Central

May, James M.; Qu, Zhi-chao

2015-01-01

Microvascular pericytes take up ascorbic acid on the ascorbate transporter SVCT2. Intracellular ascorbate then protects the cells against apoptosis induced by culture at diabetic glucose concentrations. To investigate whether pericytes might also provide ascorbate to the underlying endothelial cells, we studied ascorbate efflux from human pericytes. When loaded with ascorbate to intracellular concentrations of 0.8–1.0 mM, almost two-thirds of intracellular ascorbate effluxed from the cells over 2 h. This efflux was opposed by ascorbate re-uptake from the medium, since preventing re-uptake by destroying extracellular ascorbate with ascorbate oxidase increased ascorbate loss even further. Ascorbate re-uptake occurred on the SVCT2, since its blockade by replacing medium sodium with choline, by the SVCT2 inhibitor sulfinpyrazone, or by extracellular ascorbate accelerated ascorbate loss from the cells. This was supported by finding that net efflux of radiolabeled ascorbate was increased by unlabeled extracellular ascorbate with a half-maximal effect in the range of the high affinity Km of the SVCT2. Intracellular ascorbate did not inhibit its efflux. To assess the mechanism of ascorbate efflux, known inhibitors of volume-regulated anion channels (VRACs) were tested. These potently inhibited ascorbate transport into cells on the SVCT2, but not its efflux. An exception was the anion transport inhibitor DIDS, which, despite inhibition of ascorbate uptake, also inhibited net efflux at 25–50 µM. These results suggest that ascorbate efflux from vascular pericytes occurs on a DIDS-inhibitable transporter or channel different from VRACs. Further, ascorbate efflux is opposed by re-uptake of ascorbate on the SVCT2, providing a potential regulatory mechanism. PMID:26340060

Genotoxic effect of ethacrynic acid and impact of antioxidants

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ward, William M.; Hoffman, Jared D.; Loo, George, E-mail: g_loo@uncg.edu

It is known that ethacrynic acid (EA) decreases the intracellular levels of glutathione. Whether the anticipated oxidative stress affects the structural integrity of DNA is unknown. Therefore, DNA damage was assessed in EA-treated HCT116 cells, and the impact of several antioxidants was also determined. EA caused both concentration-dependent and time-dependent DNA damage that eventually resulted in cell death. Unexpectedly, the DNA damage caused by EA was intensified by either ascorbic acid or trolox. In contrast, EA-induced DNA damage was reduced by N-acetylcysteine and by the iron chelator, deferoxamine. In elucidating the DNA damage, it was determined that EA increased themore » production of reactive oxygen species, which was inhibited by N-acetylcysteine and deferoxamine but not by ascorbic acid and trolox. Also, EA decreased glutathione levels, which were inhibited by N-acetylcysteine. But, ascorbic acid, trolox, and deferoxamine neither inhibited nor enhanced the capacity of EA to decrease glutathione. Interestingly, the glutathione synthesis inhibitor, buthionine sulfoxime, lowered glutathione to a similar degree as EA, but no noticeable DNA damage was found. Nevertheless, buthionine sulfoxime potentiated the glutathione-lowering effect of EA and intensified the DNA damage caused by EA. Additionally, in examining redox-sensitive stress gene expression, it was found that EA increased HO-1, GADD153, and p21mRNA expression, in association with increased nuclear localization of Nrf-2 and p53 proteins. In contrast to ascorbic acid, trolox, and deferoxamine, N-acetylcysteine suppressed the EA-induced upregulation of GADD153, although not of HO-1. Overall, it is concluded that EA has genotoxic properties that can be amplified by certain antioxidants. - Highlights: • Ethacrynic acid (EA) caused cellular DNA damage. • EA-induced DNA damage was potentiated by ascorbic acid or trolox. • EA increased ROS production, not inhibited by ascorbic acid or trolox. • EA decreased glutathione levels, not prevented by ascorbic acid or trolox. • Buthionine sulfoxime intensified the DNA damage caused by EA.« less

Adjustments in CAM and enzymatic scavenging of H2O2 in juvenile plants of the epiphytic bromeliad Guzmania monostachia as affected by drought and rewatering.

PubMed

Carvalho, Victória; Abreu, Maria E; Mercier, Helenice; Nievola, Catarina C

2017-04-01

Juvenile plants of epiphytes such as bromeliads are highly prone to dehydration under drought conditions. It is likely that young epiphytes evolved mostly metabolic strategies to resist drought, which may include the plastic modulation of the enzymatic antioxidant system and crassulacean acid metabolism (CAM). Few studies have investigated such strategies in juvenile epiphytes, although such research is important to understand how these plants might face drought intensification derived from potential climatic alterations. The epiphytic CAM bromeliad Guzmania monostachia (L.) Rusby ex Mez var. monostachia is known to have plastic responses to drought, but no reports have focused on the metabolism of juvenile plants to drought and recovery. Hence, we aimed to verify how juvenile G. monostachia plants adjust malate (indicative of CAM), H 2 O 2 content and enzymatic scavenging in response to drought (eight days without irrigation) and rewatering (six days of irrigation post-drought). Interestingly, drought decreased H 2 O 2 content and activities of superoxide dismutase, catalase (CAT) and ascorbate peroxidase (APX) in the pre-dusk period, although glutathione reductase (GR) and CAM activity increased. Rewatering restored H 2 O 2 , but activities of APX, CAT and GR exceeded pre-stress levels in the pre-dusk and/or pre-dawn periods. Results suggest that recovery from a first drought redefines the homeostatic balance of H 2 O 2 scavenging, in which rewatered plants stimulate the enzymatic antioxidant system while drought-exposed plants intensify CAM activity to regulate H 2 O 2 content, a photosynthetic pathway known to prevent oxidative stress. Such data show that young G. monostachia plants adjust CAM and H 2 O 2 scavenging to adapt to water availability. Copyright © 2017 Elsevier Masson SAS. All rights reserved.

Formation, characterization, aggregation, fluorescence and antioxidant properties of novel tetrasubstituted metal-free and metallophthalocyanines bearing (4-(methylthio)phenoxy) moieties

NASA Astrophysics Data System (ADS)

Yıldırım, Nurdan; Bilgiçli, Ahmet T.; Alici, Esma Hande; Arabacı, Gulnur; Yarasir, M. Nilüfer

2017-09-01

The synthesis and characterization of peripherally tetra 4-(methylthio)phenoxy substituted metal-free(2), Zn(II) (3) and Co(II) (4) phthalocyanine derivatives were reported. These newly synthesized phthalocyanine derivatives showed the enhanced solubility in organic solvents and they were characterized by a combination of elemental analysis, FTIR, 1H NMR, 13C NMR, UV-vis and MALDI-TOF/MS spectral data. Their aggregation properties were investigated in THF by UV-vis and fluorescence. These metal-free and metallophthalocyanine compounds were also evaluated for their total antioxidant abilities by using three different antioxidant methods such as 1,1-diphenyl-2-picrylhydrazyl (DPPH) free radical scavenging, ferrous ion chelating and reducing power activity. All tested compounds showed radical scavenging activity. The highest radical scavenging activity was found from cobalt phthalocyanine (4) compound respectively. IC50 values of the compounds and standards (BHT and Trolox) were also determined. The results showed that the compound 4 had the highest antioxidant activity among all tested compounds including standards. The tested phthalocyanine compounds had ferrous ion chelating activity. In addition, they showed very high reducing power. All tested compounds had higher reducing power than the standards such as ascorbic acid and BHT. The present study shows that the synthesized tetra phthalocyanine [M: 2H(2), Zn(II)(3), Co(II)(4)] with four peripheral 4-(methylthio) phenoxy compounds have the effective antioxidant properties that can be used as antioxidant agents.

Coconut (Cocos nucifera) Ethanolic Leaf Extract Reduces Amyloid-β (1-42) Aggregation and Paralysis Prevalence in Transgenic Caenorhabditis elegans Independently of Free Radical Scavenging and Acetylcholinesterase Inhibition.

PubMed

Manalo, Rafael Vincent; Silvestre, Maries Ann; Barbosa, Aza Lea Anne; Medina, Paul Mark

2017-04-21

Virgin coconut oil (VCO) has been the subject of several studies which have aimed to alleviate Alzheimer's disease (AD) pathology, focusing on in vitro antioxidant and acetylcholinesterase (AChE) inhibitory activities. Here, we studied an underutilized and lesser-valued part of the coconut tree, specifically the leaves, using in vitro and in vivo approaches. Coconut leaf extract (CLE) was screened for antioxidant and AChE inhibitory properties in vitro and therapeutic effects in two strains of transgenic Caenorhabditis elegans expressing amyloid-β 1-42 (Aβ 1-42 ) in muscle cells. CLE demonstrated free radical scavenging activity with an EC 50 that is 79-fold less compared to ascorbic acid, and an AChE inhibitory activity that is 131-fold less compared to Rivastigmine. Surprisingly, in spite of its low antioxidant activity and AChE inhibition, CLE reduced Aβ deposits by 30.31% in CL2006 in a dose-independent manner, and reduced the percentage of paralyzed nematodes at the lowest concentration of CLE (159.38 μg/mL), compared to dH₂O/vehicle (control). Phytochemical analysis detected glycosides, anthocyanins, and hydrolyzable tannins in CLE, some of which are known to be anti-amyloidogenic. Taken together, these findings suggest that CLE metabolites alternatively decrease AB 1-42 aggregation and paralysis prevalence independently of free radical scavenging and AChE inhibition, and this warrants further investigation on the bioactive compounds of CLE.

Comparison of the response of serum ceruloplasmin and cholesterol, and of tissue ascorbic acid, metallothionein, and nonprotein sulfhydryl in rats to the dietary level of cystine and cysteine.

PubMed

Yang, B S; Yamazaki, M; Wan, Q; Kato, N

1996-12-01

The effects were compared of the addition of graded levels of L-cystine and of L-cysteine (0.3, 3, or 5%) to a 10% casein diet on several metabolic parameters in rats. The growth-promoting effect of cystine was equivalent to that of cysteine. Supplementation of these two amino acids elevated serum cholesterol, liver ascorbic acid, liver nonprotein sulfhydryl (SH) and kidney metallothionein, and reduced the activity of serum ceruloplasmin. The responses of serum cholesterol, liver nonprotein SH, and serum ceruloplasmin to cystine were greater than of those to cysteine. When the basal diet was supplemented with 0.3% of these amino acids, the elevation of liver ascorbic acid by cystine supplementation was less than that by cysteine supplementation. However, when supplemented with 5% of these amino acids, the elevation of liver ascorbic acid by cystine was greater than that by cysteine. There was no difference in the influence of cystine and cysteine on kidney metallothionein. This study demonstrates that dietary cystine and cysteine had the same influence on growth, but had a differential influence on such metabolic parameters as liver nonprotein SH, serum ceruloplasmin, serum cholesterol, and tissue ascorbic acid.

Mild concentration of ethanol in combination with ascorbic acid inhibits browning and maintains quality of fresh-cut lotus root

USDA-ARS?s Scientific Manuscript database

Aqueous solutions of ethanol and ascorbic acid alone and in combination were compared to a commonly used sanitizer, sodium hypochlorite, and a leading commercial antibrowning agent containing calcium ascorbate (CA)for their efficacy to inhibit microbial growth and browning on fresh-cut lotus root. F...

The Use of Ascorbic Acid as a Food Additive: Technical-Legal Issues

PubMed Central

Varvara, Michele; Bozzo, Giancarlo; Celano, Giuseppe; Disanto, Chiara; Pagliarone, Cosimo Nicola

2016-01-01

Ascorbic acid (C6H8O6) is an organic compound belonging to the family of monosaccharide. It is highly soluble in water, and is often called one of the secrets of the Mediterranean diet. Its use is widespread in the food industry is also important, having always been exploited for its antioxidant and stabilising ability. Many indeed are the additive formulations that take advantage of these properties. The purpose of this paper is to explain the characteristics that make ascorbic acid an important food additive and to emphasise the technical and legal issues related to its use in food productions. In particular, in the course of this employment, laws and scientific studies have been applied to the resolution of a lawsuit, having as its object the use of ascorbic acid in preparations of ground beef sold at a butcher shop. The views expressed in court by the technical consultant have led to the acquittal of the accused, in the light of the demonstrated and proven non-toxicity of the molecule and the use of a mixture of additives for the production of sausage. The European and national legislations, supported by numerous scientific studies, define the possible use of ascorbic acid according to the principle of quantum satis, and it can be used in foods for children. Our work aims to represent further evidence of the safety of use of ascorbic acid as a food additive, and – as confirmed by the legal decision reported – it wants to bring out the prospects for use of ascorbic acid for technological purposes even by registered establishments. PMID:27800425

Ascorbic acid augments colony spreading by reducing biofilm formation of methicillin-resistant Staphylococcus aureus.

PubMed

Ali Mirani, Zulfiqar; Khan, Muhammad Naseem; Siddiqui, Anila; Khan, Fouzia; Aziz, Mubashir; Naz, Shagufta; Ahmed, Ayaz; Khan, Seema Ismat

2018-02-01

Staphylococcus aureus is a Gram-positive pathogen, well known for its resistance and versatile lifestyle. Under unfavourable conditions, it adapts biofilm mode of growth. For staphylococcal biofilm formation, production of extracellular polymeric substances (EPS) is a pre-requisite, which is regulated by ica operon-encoded enzymes. This study was designed to know the impact of ascorbic acid on biofilm formation and colony spreading processes of S. aureus and MRSA. The isolates of methicillin-resistant S. aureus (MRSA) used in present study, were recovered from different food samples. Various selective and differential media were used for identification and confirmation of S. aureus . Agar dilution method was used for determination of oxacillin and ascorbic acid resistance level. MRSA isolates were re-confirmed by E-test and by amplification of mecA gene. Tube methods and Congo-Red agar were used to study biofilm formation processes. Gene expression studies were carried on real-time reverse transcriptase-polymerase chain reaction (RT-PCR). The results revealed the presence of mecA gene belonging to SCC mecA type IV along with agr type II in the isolates. In vitro studies showed the sub-inhibitory concentration of oxacillin induced biofilm production. However, addition of sub-inhibitory dose of ascorbic acid was found to inhibit EPS production, biofilm formation and augment colony spreading on soft agar plates. The inhibition of biofilm formation and augmentation of colony spreading observed with ascorbic acid alone or in combination with oxacillin. Moreover, gene expression studies showed that ascorbic acid increases agr expression and decreases icaA gene expression. The present study concluded that ascorbic acid inhibits biofilm formation, promotes colony spreading and increases agr gene expression in MRSA.

Selective Reduction of Dinitrotoluene Isomers by Ascorbate Ion. Relative Rates in Homogeneous Solution.

DTIC Science & Technology

1978-02-01

abatement Ascorbic acid TNT process Purification of dinitrotoluenes Specification grade TNT 20. ABST RACT ( C f~~.. se reverse .f ~~ If nse,ee s’ d...inexpensive carbohydrates, such that the resulting mixture , upon subsequent nitra tion , would yield specification grade TNT. Using ascorbic acid as a... acid solution, the undesired DNT isomers were considerably reduced, whereas the desired 2,4- and 2,6-DNT’s were virtually unaffected . 2 UNCLASSIFIED

Immunomodulatory Role of Ocimum gratissimum and Ascorbic Acid against Nicotine-Induced Murine Peritoneal Macrophages In Vitro

PubMed Central

Mahapatra, Santanu Kar; Chakraborty, Subhankari Prasad; Roy, Somenath

2011-01-01

The aim of this present study was to evaluate the immune functions and immune responses in nicotine-induced (10 mM) macrophages and concurrently establish the immunomodulatory role of aqueous extract of Ocimum gratissimum (Ae-Og) and ascorbic acid. In this study, nitrite generations and some phenotype functions by macrophages were studied. Beside that, release of Th1 cytokines (TNF-α, IL-12) and Th2 cytokines (IL-10, TGF-β) was measured by ELISA, and the expression of these cytokines at mRNA level was analyzed by real-time PCR. Ae-Og, at a dose of 10 μg/mL, significantly reduced the nicotine-induced NO generation and iNOSII expression. Similar kinds of response were observed with supplementation of ascorbic acid (0.01 mM). The administration of Ae-Og and ascorbic acid increased the decreased adherence, chemotaxis, phagocytosis, and intracellular killing of bacteria in nicotine-treated macrophages. Ae-Og and ascorbic acid were found to protect the murine peritoneal macrophages through downregulation of Th1 cytokines in nicotine-treated macrophages with concurrent activation of Th2 responses. These findings strongly enhanced our understanding of the molecular mechanism leading to nicotine-induced suppression of immune functions and provide additional rationale for application of anti-inflammatory therapeutic approaches by O. gratissimum and ascorbic acid for different inflammatory disease prevention and treatment during nicotine toxicity. PMID:22220218

Aortic wall damage in mice unable to synthesize ascorbic acid

PubMed Central

Maeda, Nobuyo; Hagihara, Hiroyuki; Nakata, Yukiko; Hiller, Sylvia; Wilder, Jennifer; Reddick, Robert

2000-01-01

By inactivating the gene for l-gulono-γ-lactone oxidase, a key enzyme in ascorbic acid synthesis, we have generated mice that, like humans, depend on dietary vitamin C. Regular chow, containing about 110 mg/kg of vitamin C, is unable to support the growth of the mutant mice, which require l-ascorbic acid supplemented in their drinking water (330 mg/liter). Upon withdrawal of supplementation, plasma and tissue ascorbic acid levels decreased to 10–15% of normal within 2 weeks, and after 5 weeks the mutants became anemic, began to lose weight, and die. Plasma total antioxidative capacities were approximately 37% normal in homozygotes after feeding the unsupplemented diet for 3–5 weeks. As plasma ascorbic acid decreased, small, but significant, increases in total cholesterol and decreases in high density lipoprotein cholesterol were observed. The most striking effects of the marginal dietary vitamin C were alterations in the wall of aorta, evidenced by the disruption of elastic laminae, smooth muscle cell proliferation, and focal endothelial desquamation of the luminal surface. Thus, marginal vitamin C deficiency affects the vascular integrity of mice unable to synthesize ascorbic acid, with potentially profound effects on the pathogenesis of vascular diseases. Breeding the vitamin C-dependent mice with mice carrying defined genetic mutations will provide numerous opportunities for systematic studies of the role of antioxidants in health and disease. PMID:10639167

Aortic wall damage in mice unable to synthesize ascorbic acid.

PubMed

Maeda, N; Hagihara, H; Nakata, Y; Hiller, S; Wilder, J; Reddick, R

2000-01-18

By inactivating the gene for L-gulono-gamma-lactone oxidase, a key enzyme in ascorbic acid synthesis, we have generated mice that, like humans, depend on dietary vitamin C. Regular chow, containing about 110 mg/kg of vitamin C, is unable to support the growth of the mutant mice, which require L-ascorbic acid supplemented in their drinking water (330 mg/liter). Upon withdrawal of supplementation, plasma and tissue ascorbic acid levels decreased to 10-15% of normal within 2 weeks, and after 5 weeks the mutants became anemic, began to lose weight, and die. Plasma total antioxidative capacities were approximately 37% normal in homozygotes after feeding the unsupplemented diet for 3-5 weeks. As plasma ascorbic acid decreased, small, but significant, increases in total cholesterol and decreases in high density lipoprotein cholesterol were observed. The most striking effects of the marginal dietary vitamin C were alterations in the wall of aorta, evidenced by the disruption of elastic laminae, smooth muscle cell proliferation, and focal endothelial desquamation of the luminal surface. Thus, marginal vitamin C deficiency affects the vascular integrity of mice unable to synthesize ascorbic acid, with potentially profound effects on the pathogenesis of vascular diseases. Breeding the vitamin C-dependent mice with mice carrying defined genetic mutations will provide numerous opportunities for systematic studies of the role of antioxidants in health and disease.

High dosage of ascorbic acid and alpha-tocopherol is not useful for diminishing oxidative stress and DNA damage in healthy elderly adults.

PubMed

Retana-Ugalde, Raquel; Casanueva, Esther; Altamirano-Lozano, Mario; González-Torres, Cristina; Mendoza-Núñez, Víctor Manuel

2008-01-01

To determine the useful dosage of ascorbic acid and alpha-tocopherol against oxidative stress and DNA damage in the elderly. A double-blind controlled clinical assay carried out in a sample of 66 healthy subjects divided into three age-paired random groups with 22 subjects in each group. Group A received placebo and group B was administered 500 mg of ascorbic acid and 400 IU of alpha-tocopherol, whereas group C received 1,000 mg of ascorbic acid and 400 IU of alpha-tocopherol for a 6-month period. The following measurements were performed before and after the 6-month treatment period: thiobarbituric acid reactive substances (TBARS); total antioxidant status (TAS); superoxide dismutase (SOD), and glutation peroxidase (GPx) and DNA damage by comet assay. After 6 months, group B subjects exhibited an increase in SOD and GPx enzyme levels; however, this was not statistically significant (p > 0.05). Likewise, TBARS and TAS concentrations remained unchanged (p > 0.05). In addition, in group C the decrease in TBARS and increase in SOD, GPx, and TAS were not statistically significant (p > 0.05). Similarly, average DNA migration showed no significant differences with high-dosage ascorbic acid and alpha-tocopherol. These findings suggest that administration of 1,000 mg of ascorbic acid plus 400 IU of alpha-tocopherol for 6 months is not useful for diminishing oxidative stress and DNA damage in healthy elderly adults. 2008 S. Karger AG, Basel.

Chemiluminescence behaviour of CdTe-potassium permanganate enhanced by sodium hexametaphosphate and sensitized sensing of L-ascorbic acid.

PubMed

Chen, Hongqi; Ling, Bo; Yuan, Fei; Zhou, Cailing; Chen, Jingguo; Wang, Lun

2012-01-01

A highly sensitive flow-injection chemiluminescence (FIA-CL) method based on the CdTe nanocrystals and potassium permanganate chemiluminescence system was developed for the determination of L-ascorbic acid. It was found that sodium hexametaphosphate (SP), as an enhancer, could increase the chemiluminescence (CL) emission from the redox reaction of CdTe quantum dots with potassium permanganate in near-neutral pH conditions. L-ascorbic acid is suggested as a sensitive enhancer for use in the above energy-transfer excitation process. Under optimal conditions, the calibration graph of emission intensity against logarithmic l-ascorbic acid concentration was linear in the range 1.0 × 10(-9)-5.0 × 10(-6)  mol/L, with a correlation coefficient of 0.9969 and relative standard deviation (RSD) of 2.3% (n = 7) at 5.0 × 10(-7)  mol/L. The method was successfully used to determine L-ascorbic acid in vitamin C tablets. The possible mechanism of the chemiluminescence in the system is also discussed. Copyright © 2012 John Wiley & Sons, Ltd.

Effect of natural antibrowning agents on color and related enzymes in fresh-cut Fuji apples as an alternative to the use of ascorbic acid.

PubMed

Rojas-Graü, M A; Soliva-Fortuny, R; Niartín-Belloso, O

2008-08-01

Polyphenoloxidase (PPO) and peroxidase (POD) were evaluated in fresh-cut Fuji apple slices and the effeet of the individual or combined use of ascorbic acid, 4-hexylresorcinol, N-acetylcysteine, and glutathione on their respective activities was determined. Additionally, color changes during storage at 4 degrees C were measured throughout 14 d of storage. PPO activity increased with storage time and was inhibited by the individual use of N-acetylcysteine and glutathione. POD activity in the apple slices was effectively inhibited by the combined use of ascorbic acid with any of the other antibrowning agents. On the other hand, an individual treatment with 1% N-acetylcysteine helped in maintaining the color of fresh-cut apples during 14 d of storage, whereas the use of ascorbic acid was not enough to prevent color deterioration of the apple slices from the 1st day of storage. The results obtained corroborated the effectiveness of other natural antibrowning agents over the traditional use of ascorbic acid in the control of the enzymatic browning in the fresh-cut fruit industry.

A simple 2D composite image analysis technique for the crystal growth study of L-ascorbic acid.

PubMed

Kumar, Krishan; Kumar, Virender; Lal, Jatin; Kaur, Harmeet; Singh, Jasbir

2017-06-01

This work was destined for 2D crystal growth studies of L-ascorbic acid using the composite image analysis technique. Growth experiments on the L-ascorbic acid crystals were carried out by standard (optical) microscopy, laser diffraction analysis, and composite image analysis. For image analysis, the growth of L-ascorbic acid crystals was captured as digital 2D RGB images, which were then processed to composite images. After processing, the crystal boundaries emerged as white lines against the black (cancelled) background. The crystal boundaries were well differentiated by peaks in the intensity graphs generated for the composite images. The lengths of crystal boundaries measured from the intensity graphs of composite images were in good agreement (correlation coefficient "r" = 0.99) with the lengths measured by standard microscopy. On the contrary, the lengths measured by laser diffraction were poorly correlated with both techniques. Therefore, the composite image analysis can replace the standard microscopy technique for the crystal growth studies of L-ascorbic acid. © 2017 Wiley Periodicals, Inc.

Effects of cultivar, fruit number and reflected photosynthetically active radiation on Fragaria x ananassa productivity and fruit ellagic acid and ascorbic acid concentrations.

PubMed

Atkinson, C J; Dodds, P A A; Ford, Y Y; Le Mière, J; Taylor, J M; Blake, P S; Paul, N

2006-03-01

A number of strawberry varieties were surveyed for their total ellagic acid concentration, and attempts were made to determine if ellagic acid and ascorbic acid concentrations of two strawberry cultivars could be increased by polythene reflective mulches. After adjusting crop yields and cultivation using polythene mulches with two different PAR reflective capacities, field- and polytunnel-grown strawberries were analysed for ellagic acid and ascorbic acid concentrations by HPLC. Comparative measurements of yield and fruit quality were determined along with plant developmental changes. Ellagic acid concentration varied widely with strawberry cultivar (60-341 microg g(-1) frozen weight), as did the ratio of conjugated ellagic acid : free ellagic acid. Also, there was significant year-to-year variation in total ellagic acid concentration with some cultivars. Mulches with different reflective capacities impacted on strawberry production; highly reflective mulches significantly increased growth and yield, the latter due to increases in fruit size and number. Highly reflective mulches significantly increased total concentrations of ellagic acid and ascorbic acid relative to control in fruit of different cultivars. The potential of agronomic practices to enhance the concentration and amounts of these important dietary bioactive compounds is discussed.

Design and environmentally benign synthesis of novel thiophene appended pyrazole analogues as anti-inflammatory and radical scavenging agents: Crystallographic, in silico modeling, docking and SAR characterization.

PubMed

Prabhudeva, Malledevarapura Gurumurthy; Bharath, Srinivasan; Kumar, Achutha Dileep; Naveen, Shivalingegowda; Lokanath, Neratur Krishnappagowda; Mylarappa, Bantaganahalli Ningappa; Kumar, Kariyappa Ajay

2017-08-01

Oxidative-stress induces inflammatory diseases and infections caused by drug-resistant microbial strains are on the rise necessitating the discovery of novel small-molecules for intervention therapy. The current study presents an effective and new green protocol for the synthesis of thiophene-appended pyrazoles through 3+2 annulations method. Chalcones 3(a-g) were prepared from 5-chloro-2-acetylthiophene and aromatic aldehydes by Claisen-Schmidt approach. The reaction of chalcones 3(a-g) with phenylhydrazine hydrochlorides 4(a-b) in acetic acid (30%) medium and also with freshly prepared citrus extract medium under reflux conditions produced the thiophene appended pyrazoles 5(a-l) in moderate yields. Structures of synthesized new pyrazoles were confirmed by spectral studies, elemental analysis and single crystal X-ray diffraction studies. Further, preliminary assessment of the anti-inflammatory properties of the compounds showed that, amongst the series, compounds 5d, 5e and 5l have excellent anti-inflammatory activities. Further, compounds 5c, 5d, 5g, and 5i exhibited excellent DPPH radical scavenging abilities in comparison with the standard ascorbic acid. Furthermore, using detailed structural modeling and docking efforts, combined with preliminary SAR, we show possible structural and chemical features on both the small-molecules and the protein that might contribute to the binding and inhibition. Copyright © 2017 Elsevier Inc. All rights reserved.

Formulation of a dry green tea-apple product: study on antioxidant and color stability.

PubMed

Lavelli, Vera; Vantaggi, Claudia; Corey, Mark; Kerr, William

2010-03-01

A dry apple product enriched with green tea (GT) extract was designed as a novel food to deliver relevant amounts of catechins. The target water activity (a(w)) range between 0.11 and 0.32 was chosen for the GT-fortified apple, since it corresponds to low water mobility and, consequently, maximum stability of dehydrated apples. The GT-fortified product and a control dehydrated apple product were stored in air, at 30 degrees C, and evaluated for color, antioxidant contents (monomeric flavan 3-ols, total procyanidins, ascorbic acid, chlorogenic acid and dihydrochalcones), ferric reducing/antioxidant power (FRAP), and 2,2-diphenyl-1-(2,4,6-trinitrophenyl)hydrazyl radical (DPPH) scavenging capacity. After 1 mo of storage at the lowest a(w) level (0.11), the GT-fortified product retained 80 and 100% of the initial contents of the monomeric flavan 3-ols and total procyanidins, respectively. With increasing a(w) level to 0.32, the stability of antioxidants slowly decreased. The addition of GT to the apple product increased the FRAP value and the DPPH scavenging capacity by 3.6-fold and 4.6-fold respectively, which remained almost unchanged during storage. The GT-fortified product was similar in color to commercially available dehydrated apples. Results highlighted some advantages of using dehydrated apples as a target for green tea fortification, which deserve further trials to investigate potential applications for fortification of other dehydrated fruits.

Antioxidant capacity of human blood plasma and human urine: simultaneous evaluation of the ORAC index and ascorbic acid concentration employing pyrogallol red as probe.

PubMed

Torres, P; Galleguillos, P; Lissi, E; López-Alarcón, C

2008-10-15

The oxygen radical absorbance capacity (ORAC) methodology has been employed to estimate the antioxidant capacity of human blood plasma and human urine using pyrogallol red (ORAC-PGR) as target molecule. Uric acid, reduced glutathione, human serum albumin, and ascorbic acid (ASC) inhibited the consumption of pyrogallol red, but only ASC generated an induction time. Human blood plasma and human urine protected efficiently pyrogallol red. In these assays, both biological fluids generated neat induction times that were removed by ascorbate oxidase. From these results, ORAC-PGR method could be proposed as a simple alternative to evaluate an ORAC index and, simultaneously, to estimate the concentration of ascorbic acid in human blood plasma or human urine.

Effect of turmeric powder (Curcuma longa L.) and ascorbic acid on physical characteristics and oxidative status of fresh and stored rabbit burgers.

PubMed

Mancini, Simone; Preziuso, Giovanna; Dal Bosco, Alessandro; Roscini, Valentina; Szendrő, Zsolt; Fratini, Filippo; Paci, Gisella

2015-12-01

The objective of this study was to evaluate the effect of Curcuma longa powder and ascorbic acid on some quality traits of rabbit burgers. The burgers (burgers control with no additives; burgers with 3.5 g of turmeric powder/100g meat; burgers with 0.1g of ascorbic acid/100g meat) were analyzed at Days 0 and 7 for pH, color, drip loss, cooking loss, fatty acid profile, TBARS, antioxidant capacity (ABTS, DPPH and FRAP) and microbial growth. The addition of turmeric powder modified the meat color, produced an antioxidant capacity similar to ascorbic acid and determined a lower cooking loss than other formulations. Turmeric powder might be considered as a useful natural antioxidant, increasing the quality and extending the shelf life of rabbit burgers. Copyright © 2015 Elsevier Ltd. All rights reserved.

Quantitative Determination of Citric and Ascorbic Acid in Powdered Drink Mixes

ERIC Educational Resources Information Center

Sigmann, Samuella B.; Wheeler, Dale E.

2004-01-01

A procedure by which the reactions are used to quantitatively determine the amount of total acid, the amount of total ascorbic acid and the amount of citric acid in a given sample of powdered drink mix, are described. A safe, reliable and low-cost quantitative method to analyze consumer product for acid content is provided.

Ascorbic acid metabolism during sweet cherry (Prunus avium) fruit development

PubMed Central

Ni, Zhiyou; Lin, Lijin; Tang, Yi; Wang, Zhihui; Wang, Xun; Wang, Jin; Lv, Xiulan; Xia, Hui

2017-01-01

To elucidate metabolism of ascorbic acid (AsA) in sweet cherry fruit (Prunus avium ‘Hongdeng’), we quantified AsA concentration, cloned sequences involved in AsA metabolism and investigated their mRNA expression levels, and determined the activity levels of selected enzymes during fruit development and maturation. We found that AsA concentration was highest at the petal-fall period (0 days after anthesis) and decreased progressively during ripening, but with a slight increase at maturity. AsA did nevertheless continue to accumulate over time because of the increase in fruit fresh weight. Full-length cDNAs of 10 genes involved in the L-galactose pathway of AsA biosynthesis and 10 involved in recycling were obtained. Gene expression patterns of GDP-L-galactose phosphorylase (GGP2), L-galactono-1, 4-lactone dehydrogenase (GalLDH), ascorbate peroxidase (APX3), ascorbate oxidase (AO2), glutathione reductase (GR1), and dehydroascorbate reductase (DHAR1) were in accordance with the AsA concentration pattern during fruit development, indicating that genes involved in ascorbic acid biosynthesis, degradation, and recycling worked in concert to regulate ascorbic acid accumulation in sweet cherry fruit. PMID:28245268

Prospective role of ascorbic acid (vitamin C) in attenuating hexavalent chromium-induced functional and cellular damage in rat thyroid.

PubMed

Qureshi, Irfan Zia; Mahmood, Tariq

2010-07-01

Occupational exposure to toxic heavy metals may render industrial workers with thyroid-related problems. Here, we examined the role of ascorbic acid (vitamin C) against hexavalent chromium Cr (VI)-induced damage in rat thyroid gland. Potassium dichromate (K2Cr2O7) and ascorbic acid doses were 60 microg and 120 mg kg(-1) body wt (intraperitoneally [i.p.]) respectively. Treatment regimens were group I rats, saline treated control; group II, only K2Cr2O7; group III, ascorbic acid 1 hour prior K2Cr2O7; group IV, simultaneous doses of ascorbic acid and K2Cr2O7, and group V, a combined premix dose of ascorbic acid and K2 Cr2O7 (2:1 ratio). Blood samples were taken before dosing the animals and 48 hours post exposure to determine the serum thyroid-stimulating hormone (TSH), free triiodothyronine (FT3) and free thyroxine (FT4) concentrations. Toward end of experiment, rats were sacrificed and thyroid glands were processed to evaluate the extent of cellular insult. Results showed significantly increased TSH and decreased FT3 and FT4 concentrations in groups II, III and IV rats as compared to control levels (p < 0.05). In contrast, in group V rats, serum TSH, FT3 and FT4 concentrations neared control concentrations. Histopathologically, protective effect of ascorbic acid was found in group V rats only, where thyroid gland structure neared control thyroid except the follicular size that was decreased (p < 0.05). Follicular density was no different from control. Basal laminae were intact, interfollicular spaces were normal. Colloid retraction and/or reabsorption were reduced maximally. Epithelial cell height was no different from control; epithelial follicular index increased only 1.3 fold, whereas nuclear-cytoplasmic (N/C) ratio was decreased by 14% only. The study indicates that the ascorbic acid may have the potential to protect thyroid gland from chromium toxicity; however, the study warrants further in-depth experimentation to precisely elucidate this role.

Vitamin C: update on physiology and pharmacology

PubMed Central

Mandl, J; Szarka, A; Bánhegyi, G

2009-01-01

Although ascorbic acid is an important water-soluble antioxidant and enzyme cofactor in plants and animals, humans and some other species do not synthesize ascorbate due to the lack of the enzyme catalyzing the final step of the biosynthetic pathway, and for them it has become a vitamin. This review focuses on the role of ascorbate in various hydroxylation reactions and in the redox homeostasis of subcellular compartments including mitochondria and endoplasmic reticulum. Recently discovered functions of ascorbate in nucleic acid and histone dealkylation and proteoglycan deglycanation are also summarized. These new findings might delineate a role for ascorbate in the modulation of both pro- and anti-carcinogenic mechanisms. Recent advances and perspectives in therapeutic applications are also reviewed. On the basis of new and earlier observations, the advantages of the lost ability to synthesize ascorbate are pondered. The increasing knowledge of the functions of ascorbate and of its molecular sites of action can mechanistically substantiate a place for ascorbate in the treatment of various diseases. PMID:19508394

Formation of an ascorbate-apatite composite layer on titanium.

PubMed

Ito, Atsuo; Sogo, Yu; Ebihara, Yuko; Onoguchi, Masahiro; Oyane, Ayako; Ichinose, Noboru

2007-09-01

An ascorbate-apatite composite layer was successfully formed on NaOH- and heat-treated titanium by coprecipitating L-ascorbic acid phosphate and low-crystalline apatite in a supersaturated calcium phosphate solution at 37 degrees C for 48 h. The supersaturated calcium phosphate solutions used have chemical compositions attainable by mixing infusion fluids officially approved for clinical use. The amount of immobilized L-ascorbic acid phosphate ranged from 1.0 to 2.3 microg mm(-2), which is most likely to be sufficient for the in vitro osteogenic differentiation of mesenchymal stem cells on titanium. Since ascorbate is important for the collagen synthesis and subsequent osteogenesis of mesenchymal stem cells, titanium coated with the ascorbate-apatite composite layer would be useful as a scaffold in bone tissue engineering and as a bone substitute.

Inhibition of collagen synthesis by select calcium and sodium channel blockers can be mitigated by ascorbic acid and ascorbyl palmitate

PubMed Central

Ivanov, Vadim; Ivanova, Svetlana; Kalinovsky, Tatiana; Niedzwiecki, Aleksandra; Rath, Matthias

2016-01-01

Calcium, sodium and potassium channel blockers are widely prescribed medications for a variety of health problems, most frequently for cardiac arrhythmias, hypertension, angina pectoris and other disorders. However, chronic application of channel blockers is associated with numerous side effects, including worsening cardiac pathology. For example, nifedipine, a calcium-channel blocker was found to be associated with increased mortality and increased risk for myocardial infarction. In addition to the side effects mentioned above by different channel blockers, these drugs can cause arterial wall damage, thereby contributing to vascular wall structure destabilization and promoting events facilitating rupture of plaques. Collagen synthesis is regulated by ascorbic acid, which is also essential for its optimum structure as a cofactor in lysine and proline hydroxylation, a precondition for optimum crosslinking of collagen and elastin. Therefore, the main objective in this study was to evaluate effects of various types of channel blockers on intracellular accumulation and cellular functions of ascorbate, specifically in relation to formation and extracellular deposition of major collagen types relevant for vascular function. Effects of select Na- and Ca- channel blockers on collagen synthesis and deposition were evaluated in cultured human dermal fibroblasts and aortic smooth muscle cells by immunoassay. All channel blockers tested demonstrated inhibitory effects on collagen type I deposition to the ECM by fibroblasts, each to a different degree. Ascorbic acid significantly increased collagen I ECM deposition. Nifedipine (50 µM), a representative of channel blockers tested, significantly reduced ascorbic acid and ascorbyl palmitate-dependent ECM deposition of collagen type l and collagen type lV by cultured aortic smooth muscle cells. In addition, nifedipine (50 µM) significantly reduced ascorbate-dependent collagen type l and type lV synthesis by cultured aortic smooth muscle cells, assayed by measuring intracellular collagen content. We observed increased intracellular levels of ascorbate under supplementation with elevated doses of ascorbic acid, as well as its lipid soluble derivative ascorbyl palmitate. Nifedipine reduced ascorbic acid intracellular influx in cultured aortic smooth muscle cells with nifedipine (50 µM) compared to control. Adverse effects of nifedipine were neutralized either by an increased level of cell supplementation with ascorbic acid or by substituting it with ascorbyl palmitate. These studies suggest that adverse effects of channel blockers could be caused by their weakening the arterial wall integrity by interfering with proper extracellular matrix formation. In conclusion, these studies confirm the adverse effects of channel blockers on collagen type l and lV deposition, the key ECM components essential for maintaining optimal structural integrity of the arterial walls. Ascorbate supplementation reversed channel blocker inhibition of these collagen types synthesis and deposition. The results of this study imply the benefits of ascorbate and ascorbate palmitate supplementation in medical management of cardiovascular disease in order to compensate for adverse effects of channel blockers. PMID:27335688

Inhibition of collagen synthesis by select calcium and sodium channel blockers can be mitigated by ascorbic acid and ascorbyl palmitate.

PubMed

Ivanov, Vadim; Ivanova, Svetlana; Kalinovsky, Tatiana; Niedzwiecki, Aleksandra; Rath, Matthias

2016-01-01

Calcium, sodium and potassium channel blockers are widely prescribed medications for a variety of health problems, most frequently for cardiac arrhythmias, hypertension, angina pectoris and other disorders. However, chronic application of channel blockers is associated with numerous side effects, including worsening cardiac pathology. For example, nifedipine, a calcium-channel blocker was found to be associated with increased mortality and increased risk for myocardial infarction. In addition to the side effects mentioned above by different channel blockers, these drugs can cause arterial wall damage, thereby contributing to vascular wall structure destabilization and promoting events facilitating rupture of plaques. Collagen synthesis is regulated by ascorbic acid, which is also essential for its optimum structure as a cofactor in lysine and proline hydroxylation, a precondition for optimum crosslinking of collagen and elastin. Therefore, the main objective in this study was to evaluate effects of various types of channel blockers on intracellular accumulation and cellular functions of ascorbate, specifically in relation to formation and extracellular deposition of major collagen types relevant for vascular function. Effects of select Na- and Ca- channel blockers on collagen synthesis and deposition were evaluated in cultured human dermal fibroblasts and aortic smooth muscle cells by immunoassay. All channel blockers tested demonstrated inhibitory effects on collagen type I deposition to the ECM by fibroblasts, each to a different degree. Ascorbic acid significantly increased collagen I ECM deposition. Nifedipine (50 µM), a representative of channel blockers tested, significantly reduced ascorbic acid and ascorbyl palmitate-dependent ECM deposition of collagen type l and collagen type lV by cultured aortic smooth muscle cells. In addition, nifedipine (50 µM) significantly reduced ascorbate-dependent collagen type l and type lV synthesis by cultured aortic smooth muscle cells, assayed by measuring intracellular collagen content. We observed increased intracellular levels of ascorbate under supplementation with elevated doses of ascorbic acid, as well as its lipid soluble derivative ascorbyl palmitate. Nifedipine reduced ascorbic acid intracellular influx in cultured aortic smooth muscle cells with nifedipine (50 µM) compared to control. Adverse effects of nifedipine were neutralized either by an increased level of cell supplementation with ascorbic acid or by substituting it with ascorbyl palmitate. These studies suggest that adverse effects of channel blockers could be caused by their weakening the arterial wall integrity by interfering with proper extracellular matrix formation. In conclusion, these studies confirm the adverse effects of channel blockers on collagen type l and lV deposition, the key ECM components essential for maintaining optimal structural integrity of the arterial walls. Ascorbate supplementation reversed channel blocker inhibition of these collagen types synthesis and deposition. The results of this study imply the benefits of ascorbate and ascorbate palmitate supplementation in medical management of cardiovascular disease in order to compensate for adverse effects of channel blockers.

Enhancement of neurite outgrowth in PC12 cells stimulated with cyclic AMP and NGF by 6-acylated ascorbic acid 2-O-alpha-glucosides (6-Acyl-AA-2G), novel lipophilic ascorbate derivatives.

PubMed

Zhou, Xiaohua; Tai, Akihiro; Yamamoto, Itaru

2003-03-01

It has been shown that ascorbate (AsA) and its stable derivative, ascorbic acid 2-O-alpha-glucoside (AA-2G), do not elicit neurite outgrowth in PC12 cells. However, these ascorbates are synergistically enhanced by both dibutyryl cyclic AMP (Bt(2)cAMP)- and nerve growth factor (NGF)-induced neurite outgrowth in this model. In the present study, the effects of a series of novel lipophilic ascorbate derivatives, 6-acylated ascorbic acid 2-O-alpha-glucosides (6-Acyl-AA-2G), on neurite outgrowth induced by Bt(2)cAMP and NGF were examined in PC12 cells. We found that all the tested acylated ascorbate derivatives enhanced neurite formation induced by both agents in a dose-dependent manner. Of the 6-Acyl-AA-2G derivatives, 6-octanoyl ascorbic acid 2-O-alpha-glucoside (6-Octa-AA-2G) enhanced the Bt(2)cAMP-induced phosphorylated MAPK p44 and p42 expression. A alpha-glucosidase inhibitor, castanospermine, completely abrogated the promotion of neurite outgrowth and MAPK expression by 6-Octa-AA-2G. Addition of 6-Octa-AA-2G (0.5 mM) to PC12 cells caused a rapid and significant increase in intracellular AsA content, which reached a maximum and was maintained from 12 to 24 h after the culture. These findings suggest that 6-Acyl-AA-2G is rapidly hydrolyzed to AsA within the cell and enhances neurite differentiation through the interaction with the inducer-activated MAPK pathway.

[Cellular and intracellular transport of vitamin C. The physiologic aspects].

PubMed

Szarka, András; Lőrincz, Tamás

2013-10-20

Vitamin C requirement is satisfied by natural sources and vitamin C supplements in the ordinary human diet. The two major forms of vitamin C in the diet are L-ascorbic acid and L-dehydroascorbic acid. Both ascorbate and dehydroascorbate are absorbed along the entire length of the human intestine. The reduced form, L-ascorbic acid is imported by an active mechanism, requiring two sodium-dependent vitamin C transporters (SVCT1 and SVCT2). The transport of the oxidized form, dehydroascorbate is mediated by glucose transporters GLUT1, GLUT3 and possibly GLUT4. Initial rate of uptake of both ascorbate and dehydroascorbate is saturable with increasing external substrate concentration. Vitamin C plasma concentrations are tightly controlled when the vitamin is taken orally. It has two simple reasons, on the one hand, the capacity of the transporters is limited, on the other hand the two Na+-dependent transporters can be down-regulated by an elevated level of ascorbate.

Effect of gamma irradiation in presence of ascorbic acid on microbial composition and TBARS concentration of ground beef coated with an edible active coating

NASA Astrophysics Data System (ADS)

Lacroix, M.; Ouattara, B.; Saucier, L.; Giroux, M.; Smoragiewicz, W.

2004-09-01

The present study was conducted to evaluate the combined effect of gamma irradiation in presence of ascorbic acid on the microbiological characteristics and thiobarbituric acid-reactive substances (TBARS) concentration of ground beef coated with an edible coating, crosslinked by gamma irradiation. The medium fat ground beef patties (23% fat ) were divided into two separate treatment groups: (i) control (ground beef without additive), (ii) ground beef with 0.5% (w/w) ascorbic acid. Meat samples were irradiated at doses of 0, 1, 2, and 3 kGy and stored at 4±2°C. The content of TBARS was evaluated. After 7 days of storage, Enterobacteriaceae, presumptive Staphylococcus aureus, presumptive Pseudomonas spp., Brochothrix thermosphacta and lactic acid bacteria were enumerated. Results showed that lactic acid bacteria and Br. thermosphacta were more resistant to irradiation than Enterobacteriaceae and Pseudomonas. The content in TBARS was stabilized during post-irradiation storage for samples containing ascorbic acid. Shelf life extension periods estimated on the basis of a limit level of 6 log CFU/g for APCs were 4, 7, and 10 days for samples irradiated at 1, 2, and 3 kGy, respectively. However, the incorporation of ascorbic acid in ground beef did not improve significantly ( p>0.05) the inhibitory effect of gamma irradiation.

Comparison of bioactive components in fresh, pressurized, pasteurized and sterilized pennywort (Centella asiatica L.) juices

NASA Astrophysics Data System (ADS)

Apichartsrangkoon, Arunee; Chattong, Utaiwan; Chunthanom, Pornprapa

2012-06-01

The biologically active constituents of pennywort juice were analyzed by HPLC. The juice extract contained the bioactive glycosides, including asiaticoside and madecassoside. Antioxidant properties of juices were determined in terms of ferric-reducing antioxidant power assay, total polyphenol, β-carotene and ascorbic acid contents. After processing, asiaticoside, madecassoside and β-carotene in the extracted juice were relatively stable with no significant losses occurring. Pressurization could significantly retain ascorbic acid, polyphenols and antioxidant capacity than those pasteurization or sterilization. For storage assessment, asiaticoside in the processed juices was relatively stable during 4 months storage. Losses of ascorbic acid in the pressurized juice during storage were greater than in pasteurized and sterilized juice. However, the total amount of ascorbic acid retained in pressurized juice was still higher than those thermal-treated products.

Effect of edible coatings on bioactive compounds and antioxidant capacity of tomatoes at different maturity stages.

PubMed

Dávila-Aviña, Jorge E; Villa-Rodríguez, José A; Villegas-Ochoa, Mónica A; Tortoledo-Ortiz, Orlando; Olivas, Guadalupe I; Ayala-Zavala, J Fernando; González-Aguilar, Gustavo A

2014-10-01

This work evaluated the effect of carnauba and mineral oil coatings on the bioactive compounds and antioxidant capacity of tomato fruits (cv. "Grandela"). Carnauba and mineral oil coatings were applied on fresh tomatoes at two maturity stages (breaker and pink) over 28 day of storage at 10 °C was evaluated. Bioactive compound and antioxidant activity assays included total phenols, total flavonoids, ascorbic acid (ASA), lycopene, DPPH radical scavenging activity (%RSA), trolox equivalent antioxidant capacity (TEAC) and oxygen radical absorbance capacity assay (ORAC). The total phenolic, flavonoid and lycopene contents were significantly lower for coated fruit than control fruits. However, ascorbic acid content was highest in fruits treated with carnauba, followed by mineral oil coating and control fruits. The ORAC values were highest in breaker tomatoes coated with carnauba wax, followed by mineral oil-coated fruits and controls. No significant differences in ORAC values were observed in pink tomatoes. % RSA and TEAC values were higher for controls than for coated fruit. Edible coatings preserve the overall quality of tomatoes during storage without affecting the nutritional quality of fruit. We found that the physiological response to the coatings is in function of the maturity stage of tomatoes. The information obtained in this study support to use of edible coating as a safe and good alternative to preserve tomato quality, and that the changes of bioactive compounds and antioxidant activity of tomato fruits, was not negatively affected. This approach can be used by producers to preserve tomato quality.

Effects of Nigella sativa oil and ascorbic acid against oxytetracycline-induced hepato-renal toxicity in rabbits.

PubMed

Abdel-Daim, Mohamed M; Ghazy, Emad W

2015-03-01

Oxytetracycline (OTC) is a broad spectrum antibiotic widely used for treatment of a wide range of infections. However, its improper human and animal use leads to toxic effects, including hepatonephrotoxicity. Our objective was to evaluate protective effects of Nigella sativa oil (NSO) and/or ascorbic acid (AA), against OTC-induced hepatonephrotoxicity in rabbits. Forty male white New Zealand rabbits were divided into 5 groups of eight each. The 1(st) group (control) was given saline. The 2(nd) group was given OTC (200 mg/kg, orally). The 3(rd) and 4(th) groups were orally administered NSO and AA (2 ml/kg and 200 mg/kg respectively) 1 hr before OTC administration at the same dose regimen used for the 2(nd) group. Both NSO and AA were given in combination for the 5(th) group along with OTC administration. Serum biochemical parameters related to liver and kidney injury were evaluated, and lipid peroxidation as well as antioxidant markers in hepatic and renal tissues were examined. OTC-treated animals revealed significant alterations in serum biochemical hepato-renal injury markers, and showed a markedly increase in hepato-renal lipid peroxidation and inhibition in tissue antioxidant biomarkers. NSO and AA protect against OTC-induced serum and tissue biochemical alterations when each of them is used alone or in combination along with OTC treatment. Furthermore, both NSO and AA produced synergetic hepatoprotective and antioxidant properties. The present study revealed the preventive role of NSO and/or AA against the toxic effects of OTC through their free radical-scavenging and potent antioxidant activities.

Antioxidant and Antifungal Activity of Extracts of the Aerial Parts of Thymus capitatus (L.) Hoffmanns Against Four Phytopathogenic Fungi of Citrus sinensis

PubMed Central

Tabti, Leila; Dib, Mohammed El Amine; Gaouar, Nassira; Samira, Bouayad; Tabti, Boufeldja

2014-01-01

Background: Many medicinal plants from the Lamiaceae family can be easily found in Algeria. These plants have been used as traditional medicines by local ethnic groups. Thymus capitatus is known in Algeria as "Zaatar" and has been commonly used as a spice, and reported to have many biological effects. Objectives: This paper focused on the assessment of the antioxidant potential and antifungal activity of essential oil and solvent extracts of T. capitatus against the growth of certain fungi. Materials and Methods: Essential oil, ethanol and hexane extracts of T. capitatus were tested for their antioxidant and antifungal activities. The 2, 2-diphenyl-1-picrylhydrazyl (DPPH) assay was used to determine the free radical quenching capacity. Antifungal activity was assessed using the radial growth technique. Results: DPPH free radical scavenging effect of the extracts was compared with standard antioxidant ascorbic acid and showed significant results. The ethanol extract showed high activity at the concentration of 80 g/mL, but less than the standard ascorbic acid. The essential oil was effective against all the fungi used in the experiment. The highest inhibitory effect on the growth of Aspergillus niger, Aspergillus oryzae, Penicillium digitatum, and Fusarium solani was exhibited by the essential oil at concentrations between 0.1 and 0.5 μg/mL. Conclusions: These findings demonstrated that ethanol extract obtained from T. capitatus is a potential source of natural antioxidant, while the essential oil extract can be exploited as an ideal alternative to synthetic fungicides for use in the treatment of many fungal phytopathogens. PMID:24644439

Ascorbic acid supplementation diminishes microparticle elevations and neutrophil activation following SCUBA diving.

PubMed

Yang, Ming; Barak, Otto F; Dujic, Zeljko; Madden, Dennis; Bhopale, Veena M; Bhullar, Jasjeet; Thom, Stephen R

2015-08-15

Predicated on evidence that diving-related microparticle generation is an oxidative stress response, this study investigated the role that oxygen plays in augmenting production of annexin V-positive microparticles associated with open-water SCUBA diving and whether elevations can be abrogated by ascorbic acid. Following a cross-over study design, 14 male subjects ingested placebo and 2-3 wk later ascorbic acid (2 g) daily for 6 days prior to performing either a 47-min dive to 18 m of sea water while breathing air (∼222 kPa N2/59 kPa O2) or breathing a mixture of 60% O2/balance N2 from a tight-fitting face mask at atmospheric pressure for 47 min (∼40 kPa N2/59 kPa O2). Within 30 min after the 18-m dive in the placebo group, neutrophil activation, and platelet-neutrophil interactions occurred, and the total number of microparticles, as well as subgroups bearing CD66b, CD41, CD31, CD142 proteins or nitrotyrosine, increased approximately twofold. No significant elevations occurred among divers after ingesting ascorbic acid, nor were elevations identified in either group after breathing 60% O2. Ascorbic acid had no significant effect on post-dive intravascular bubble production quantified by transthoracic echocardiography. We conclude that high-pressure nitrogen plays a key role in neutrophil and microparticle-associated changes with diving and that responses can be abrogated by dietary ascorbic acid supplementation. Copyright © 2015 the American Physiological Society.

Ascorbic acid co-administered with rosuvastatin reduces reproductive impairment in the male offspring from male rats exposed to the statin at pre-puberty.

PubMed

Leite, Gabriel Adan Araújo; Figueiredo, Thamiris Moreira; Guerra, Marina Trevizan; Borges, Cibele Dos Santos; Fernandes, Fábio Henrique; Anselmo-Franci, Janete Aparecida; Kempinas, Wilma De Grava

2018-05-18

Obesity during childhood and adolescence is closely related to dysfunctions on lipid profile in children. Rosuvastatin is a statin that decreases serum total cholesterol. Ascorbic acid is an important antioxidant compound for male reproduction. Pre-pubertal male rats were distributed into six experimental groups that received saline solution 0.9% (vehicle), 3 or 10 mg/kg/day of rosuvastatin, 150 mg/day of ascorbic acid, or 3 or 10 mg/kg/day of rosuvastatin co-administered with 150 mg/day of ascorbic acid by gavage from post-natal day (PND)23 until PND53. Rats were maintained until adulthood and mated with nulliparous females to obtain the male offspring, whose animals were evaluated at adulthood in relation to reproductive parameters. This study is a follow up of a previous paper addressing potential effects on F0 generation only (Leite et al., 2017). Male offspring from rosuvastatin-exposed groups showed increased sperm DNA fragmentation, androgen depletion and impairment on the testicular and epididymal structure. Ascorbic acid coadministered to the fathers ameliorated the reproductive damage in the offspring. In summary, paternal exposure to rosuvastatin may affect the reproduction in the male offspring; however, paternal supplementation with ascorbic acid was able to reduce the reproductive impairment in the male offspring caused by statin treatment to the fathers. Copyright © 2018 Elsevier Ltd. All rights reserved.

Green reduction of graphene oxide by ascorbic acid

NASA Astrophysics Data System (ADS)

Khosroshahi, Zahra; Kharaziha, Mahshid; Karimzadeh, Fathallah; Allafchian, Alireza

2018-01-01

Graphene, a single layer of sp2-hybridized carbon atoms in a hexagonal (two-dimensional honey-comb) lattice, has attracted strong scientific and technological interest due to its novel and excellent optical, chemical, electrical, mechanical and thermal properties. The solution-processable chemical reduction of Graphene oxide (GO is considered as the most favorable method regarding mass production of graphene. Generally, the reduction of GO is carried out by chemical approaches using different reductants such as hydrazine and sodium borohydride. These components are corrosive, combustible and highly toxic which may be dangerous for personnel health and the environment. Hence, these reducing agents are not promising choice for reducing of graphene oxide (GO). As a consequence, it is necessary for further development and optimization of eco-friendly, natural reducing agent for clean and effective reduction of GO. Ascorbic acid, an eco-friendly and natural reducing agents, having a mild reductive ability and nontoxic property. So, the aim of this research was to green synthesis of GO with ascorbic acid. For this purpose, the required amount of NaOH and ascorbic acid were added to GO solution (0.5 mg/ml) and were heated at 95 °C for 1 hour. According to the X-ray powder diffraction (XRD), scanning electron microscopy (SEM), and electrochemical results, GO were reduced with ascorbic acid like hydrazine with better electrochemical properties and ascorbic acid is an ideal substitute for hydrazine in the reduction of graphene oxide process.

Composition and antioxidant, antibacterial, and anti-HepG2 cell activities of polyphenols from seed coat of Amygdalus pedunculata Pall.

PubMed

Lu, Cairui; Li, Cong; Chen, Bang; Shen, Yehua

2018-11-01

This study aims at identifying the composition of polyphenols present in Amygdalus pedunculata Pall seed coat (APSC), and characterizing their antioxidant, antibacterial, and anticancer activities. The polyphenols from APSC were composed of 32 compounds. The compounds with important biological activities included apigenin 7-O-glucoside (the main component; 34.53 mg/100 g), quercitrin (23.43 mg/100 g), kaempferol (10.28 mg/100 g), naringenin (6.27 mg/100 g), cyanidin 3-rutinoside (5.76 mg/100 g), cyanidin 3-O-galactoside (5.19 mg/100 g), and quercetin (2.50 mg/100 g), as well as a variety of phenolic acids (gentisic acid, 23.13 mg/100 g; salicylic acid, 18.79 mg/100 g; gallic acid, 2.55 mg/100 g; etc.). Characterization of the identified polyphenols indicated that APSC possessed high antioxidant activity, due to its ability to reduce Fe 3+ and scavenge ABTS, DPPH, OH, O 2 - , and H 2 O 2 free radicals. The ability of APSC to reduce Fe 3+ and scavenge ABTS radical, and H 2 O 2 was stronger than that of control group ascorbic acid (Vc). The data from bacteriostatic test showed that polyphenols from APSC had good antibacterial activity against Escherichia coli, Staphylococcus aureus, Bacillus cereus, and Bacillus subtilis, but showed no activity against Aspergillus niger. Cell viability assays using HepG2 cell illustrated that polyphenols from APSC significantly inhibited cell proliferation and induced cell apoptosis. The findings demonstrate that polyphenols from APSC may be utilized as is or further developed into natural antioxidant, antibacterial, and anticancer agents. This work also provides a basis for the development and utilization of Amygdalus pedunculata Pall. Copyright © 2018 Elsevier Ltd. All rights reserved.

Oxidative stress and acute-phase response in patients with pressure sores.

PubMed

Cordeiro, Maria Bernarda Cavalcanti; Antonelli, Elida Juliana; da Cunha, Daniel Ferreira; Júnior, Alceu Afonso Jordão; Júnior, Virmondes Rodrigues; Vannucchi, Helio

2005-09-01

We investigated the relation between oxidative stress and the occurrence of the acute-phase response with serum ascorbic acid and alpha-tocopherol levels in patients with pressure sores. The following groups of patients were studied: 1) those who had patients with pressure sores, 2) those who had pneumonia, and 3) those who did not develop pressure sores or any type of infection (control). Concentrations of total proteins, albumin, creatinine, iron, ferritin, transferrin, C-reactive protein, alpha1-acid glycoprotein, total iron-binding capacity, ascorbic acid, alpha-tocopherol, and malondialdehyde were measured during the first days of hospitalization. Albumin concentrations were significantly lower (P < 0.05) and C-reactive protein concentrations were significantly higher (P < 0.05) in patients with pressure sores compared with controls. Concentrations of ascorbic acid and alpha-tocopherol were significantly decreased (P < 0.05) in patients who had pressure sores or infection, whereas malondialdehyde concentrations were significantly increased (P < 0.05) compared with control patients. Five of 11 patients (55.56%) with pressure sores and 10 of 12 patients (83.33%) with pneumonia presented serum ascorbic acid concentrations below the reference value (34 to 91 micromol/L). Concentrations of ascorbic acid and alpha-tocopherol versus malondialdehyde were significantly correlated in the three patient groups (r = -0.44, P < 0.05; r = -0.55, P < 0.01, respectively). Patients with pressure sores and acute infection present a systemic inflammatory response accompanied by an increase in lipid peroxidation that is associated with decreased serum ascorbic acid and alpha-tocopherol levels, suggesting that these patients may be at risk for important nutritional deficiencies.

Ascorbate degradation in tomato leads to accumulation of oxalate, threonate and oxalyl threonate.

PubMed

Truffault, Vincent; Fry, Stephen C; Stevens, Rebecca G; Gautier, Hélène

2017-03-01

Ascorbate content in plants is controlled by its synthesis from carbohydrates, recycling of the oxidized forms and degradation. Of these pathways, ascorbate degradation is the least studied and represents a lack of knowledge that could impair improvement of ascorbate content in fruits and vegetables as degradation is non-reversible and leads to a depletion of the ascorbate pool. The present study revealed the nature of degradation products using [ 14 C]ascorbate labelling in tomato, a model plant for fleshy fruits; oxalate and threonate are accumulated in leaves, as is oxalyl threonate. Carboxypentonates coming from diketogulonate degradation were detected in relatively insoluble (cell wall-rich) leaf material. No [ 14 C]tartaric acid was found in tomato leaves. Ascorbate degradation was stimulated by darkness, and the degradation rate was evaluated at 63% of the ascorbate pool per day, a percentage that was constant and independent of the initial ascorbate or dehydroascorbic acid concentration over periods of 24 h or more. Furthermore, degradation could be partially affected by the ascorbate recycling pathway, as lines under-expressing monodehydroascorbate reductase showed a slight decrease in degradation product accumulation. © 2016 The Authors The Plant Journal © 2016 John Wiley & Sons Ltd.

An Indian Desert Shrub 'Hiran Chabba', Farsetia Hamiltonii Royle, Exhibits Potent Antioxidant and Hepatoprotective Effect Against Iron-Overload Induced Liver Toxicity in Swiss Albino Mice.

PubMed

Basu, Tapasree; Kumar, Bipul; Shendge, Anil Khushalrao; Panja, Sourav; Chugh, Heerak; Gautam, Hemant K; Mandal, Nripendranath

2018-04-18

Farsetia hamiltonii Royle, also known as Hiran Chabba grows in desert regions. It is widely used as folk medicine to treat joint pains, diarrhea and diabetes. However, its antioxidant and iron chelation abilities both in vitro and in vivo have not yet been investigated. The 70% methanolic extract of F.hamiltonii (FHME) was investigated for its free radical scavenging and iron chelation potential, in vitro. An iron-overload situation was established by intraperitoneal injection of iron-dextran in Swiss albino mice, followed by oral administration of FHME. Liver damage and serum parameters due to iron-overload were measured biochemically and histopathologically to test iron-overload remediation and hepatoprotective potential of FHME. Phytochemical analyses were performed to determine its probable bioactive components. FHME showed promising antioxidant activity, scavenged various reactive oxygen and nitrogen species and chelated iron in vitro. FHME reduced liver iron, serum ferritin, normalized serum parameters, reduced oxidative stress in liver, serum and improved liver antioxidant status in iron-overloaded mice. It also alleviated liver damage and fibrosis as evident from biochemical parameters and morphological analysis of liver sections. The phytochemical analyses of FHME reflected the presence of alkaloids, phenols, flavonoids and tannins. HPLC analysis indicated presence of tannic acid, quercetin, methyl gallate, catechin, reserpine, ascorbic acid and gallic acid. Based on the experimental outcome, FHME, an ethnologically important plant can be envisaged as excellent antioxidant and iron chelator drug capable of remediating iron-overload induced hepatotoxicity and the bioactive compounds present in FHME might be responsible for its efficacy. Copyright© Bentham Science Publishers; For any queries, please email at epub@benthamscience.org.

Transcriptome analysis of Pinus halepensis under drought stress and during recovery

PubMed Central

Fox, Hagar; Doron-Faigenboim, Adi; Kelly, Gilor; Bourstein, Ronny; Attia, Ziv; Zhou, Jing; Moshe, Yosef; Moshelion, Menachem; David-Schwartz, Rakefet

2018-01-01

Abstract Forest trees use various strategies to cope with drought stress and these strategies involve complex molecular mechanisms. Pinus halepensis Miller (Aleppo pine) is found throughout the Mediterranean basin and is one of the most drought-tolerant pine species. In order to decipher the molecular mechanisms that P. halepensis uses to withstand drought, we performed large-scale physiological and transcriptome analyses. We selected a mature tree from a semi-arid area with suboptimal growth conditions for clonal propagation through cuttings. We then used a high-throughput experimental system to continuously monitor whole-plant transpiration rates, stomatal conductance and the vapor pressure deficit. The transcriptomes of plants were examined at six physiological stages: pre-stomatal response, partial stomatal closure, minimum transpiration, post-irrigation, partial recovery and full recovery. At each stage, data from plants exposed to the drought treatment were compared with data collected from well-irrigated control plants. A drought-stressed P. halepensis transcriptome was created using paired-end RNA-seq. In total, ~6000 differentially expressed, non-redundant transcripts were identified between drought-treated and control trees. Cluster analysis has revealed stress-induced down-regulation of transcripts related to photosynthesis, reactive oxygen species (ROS)-scavenging through the ascorbic acid (AsA)-glutathione cycle, fatty acid and cell wall biosynthesis, stomatal activity, and the biosynthesis of flavonoids and terpenoids. Up-regulated processes included chlorophyll degradation, ROS-scavenging through AsA-independent thiol-mediated pathways, abscisic acid response and accumulation of heat shock proteins, thaumatin and exordium. Recovery from drought induced strong transcription of retrotransposons, especially the retrovirus-related transposon Tnt1-94. The drought-related transcriptome illustrates this species’ dynamic response to drought and recovery and unravels novel mechanisms. PMID:29177514

Hypolipidemic and Antioxidative Effects of Aqueous Enzymatic Extract from Rice Bran in Rats Fed a High-Fat and -Cholesterol Diet

PubMed Central

Wang, Yu-Xin; Li, Yang; Sun, An-Min; Wang, Feng-Jiao; Yu, Guo-Ping

2014-01-01

Purpose: The aqueous enzymatic extract from rice bran (AEERB) was rich in protein, γ-oryzanol and tocols. The aim of this study was to investigate the effects of AEERB on the regulation of lipid metabolism and the inhibition of oxidative damage. Methods: The antioxidant activity of AEERB in vitro was measured in terms of radical scavenging capacity, ferric reducing ability power (FRAP) and linoleic acid emulsion system-ferric thiocyanate method (FTC). Male Wistar rats were fed with a normal diet and a high-fat and high-cholesterol diet with or without AEERB. After treatment, biochemical assays of serum, liver and feces lipid levels, the antioxidant enzyme activity, malondialdehyde (MDA) and protein carbonyl were determined. Result: AEERB is completely soluble in water and rich in hydrophilic and lipophilic functional ingredients. AEERB scavenged DPPH• and ABTS•+ and exhibited antioxidant activity slightly lower than that of ascorbic acid in the linoleic acid system. The administration of AEERB reduced serum lipid levels and the atherogenic index compared with those of the hyperlipidemic diet group (HD). The administration of AEERB significantly lowered liver lipid levels, inhibited hepatic 3-hydroxyl-3-methylglutaryl CoA reductase activity, and efficiently promoted the fecal excretion of total lipids and total cholesterol (TC) (p < 0.05). Dietary AEERB enhanced antioxidant status in the serum, liver and brain by increasing the antioxidant enzyme activity of superoxide dismutase (SOD), catalase (CAT), and glutathione peroxidase (GSH-Px) and decreasing the content of MDA and protein carbonyl. Conclusions: The results indicated that AEERB might act as a potent hypolipidemic and antioxidant functional food. PMID:25230211

Antioxidant Properties of Kynurenines: Density Functional Theory Calculations

PubMed Central

2016-01-01

Kynurenines, the main products of tryptophan catabolism, possess both prooxidant and anioxidant effects. Having multiple neuroactive properties, kynurenines are implicated in the development of neurological and cognitive disorders, such as Alzheimer's, Parkinson's, and Huntington's diseases. Autoxidation of 3-hydroxykynurenine (3HOK) and its derivatives, 3-hydroxyanthranilic acid (3HAA) and xanthommatin (XAN), leads to the hyperproduction of reactive oxygen species (ROS) which damage cell structures. At the same time, 3HOK and 3HAA have been shown to be powerful ROS scavengers. Their ability to quench free radicals is believed to result from the presence of the aromatic hydroxyl group which is able to easily abstract an electron and H-atom. In this study, the redox properties for kynurenines and several natural and synthetic antioxidants have been calculated at different levels of density functional theory in the gas phase and water solution. Hydroxyl bond dissociation enthalpy (BDE) and ionization potential (IP) for 3HOK and 3HAA appear to be lower than for xanthurenic acid (XAA), several phenolic antioxidants, and ascorbic acid. BDE and IP for the compounds with aromatic hydroxyl group are lower than for their precursors without hydroxyl group. The reaction rate for H donation to *O-atom of phenoxyl radical (Ph-O*) and methyl peroxy radical (Met-OO*) decreases in the following rankings: 3HOK ~ 3HAA > XAAOXO > XAAENOL. The enthalpy absolute value for Met-OO* addition to the aromatic ring of the antioxidant radical increases in the following rankings: 3HAA* < 3HOK* < XAAOXO* < XAAENOL*. Thus, the high free radical scavenging activity of 3HAA and 3HOK can be explained by the easiness of H-atom abstraction and transfer to O-atom of the free radical, rather than by Met-OO* addition to the kynurenine radical. PMID:27861556

Transcriptome analysis of Pinus halepensis under drought stress and during recovery.

PubMed

Fox, Hagar; Doron-Faigenboim, Adi; Kelly, Gilor; Bourstein, Ronny; Attia, Ziv; Zhou, Jing; Moshe, Yosef; Moshelion, Menachem; David-Schwartz, Rakefet

2018-03-01

Forest trees use various strategies to cope with drought stress and these strategies involve complex molecular mechanisms. Pinus halepensis Miller (Aleppo pine) is found throughout the Mediterranean basin and is one of the most drought-tolerant pine species. In order to decipher the molecular mechanisms that P. halepensis uses to withstand drought, we performed large-scale physiological and transcriptome analyses. We selected a mature tree from a semi-arid area with suboptimal growth conditions for clonal propagation through cuttings. We then used a high-throughput experimental system to continuously monitor whole-plant transpiration rates, stomatal conductance and the vapor pressure deficit. The transcriptomes of plants were examined at six physiological stages: pre-stomatal response, partial stomatal closure, minimum transpiration, post-irrigation, partial recovery and full recovery. At each stage, data from plants exposed to the drought treatment were compared with data collected from well-irrigated control plants. A drought-stressed P. halepensis transcriptome was created using paired-end RNA-seq. In total, ~6000 differentially expressed, non-redundant transcripts were identified between drought-treated and control trees. Cluster analysis has revealed stress-induced down-regulation of transcripts related to photosynthesis, reactive oxygen species (ROS)-scavenging through the ascorbic acid (AsA)-glutathione cycle, fatty acid and cell wall biosynthesis, stomatal activity, and the biosynthesis of flavonoids and terpenoids. Up-regulated processes included chlorophyll degradation, ROS-scavenging through AsA-independent thiol-mediated pathways, abscisic acid response and accumulation of heat shock proteins, thaumatin and exordium. Recovery from drought induced strong transcription of retrotransposons, especially the retrovirus-related transposon Tnt1-94. The drought-related transcriptome illustrates this species' dynamic response to drought and recovery and unravels novel mechanisms.

Effects of ascorbic acid enrichment by immersion of rainbow trout (Oncorhynchus mykiss, Walbaum 1792) eggs and embryos

USGS Publications Warehouse

Falahatkar, B.; Dabrowski, K.; Arslan, M.; Rinchard, J.

2006-01-01

This study was conducted to examine the effects of different forms and concentrations of ascorbic acid (vitamin C), and different enrichment times (24 and 48 h post ovulation) on egg, embryo and alevin ascorbate concentrations and survival of rainbow trout (enrichment was at the ova stage). In experiments 1 and 2, fertilized eggs were immersed in water containing ascorbate at 0 (control), 100, 1000 mg L-1 l-ascorbic acid (AA) and 2000 mg L -1 l-ascorbyl monophosphate (AP). In experiment 3, 0 (control), 500 and 1000 mg L-1 AA neutralized (N) with NaOH, 1000 mg L-1 AA non-neutralized (NN), 1000 and 2000 mg L-1 AP immersions were used. The mean total ascorbic acid (TAA) and dehydroascorbic acid (DHA) concentrations were measured before fertilization, at 3 and 24 h after fertilization, at the eyed stage, and in hatched alevins. We observed significant differences in TAA concentration at different immersion levels at 3 and 24 h after fertilization. Survival decreased significantly depending on the level of vitamin C, pH of the solutions and immersion time. We suggest that when broodstock rainbow trout do not have enough vitamin C in their ovaries, immersion of eggs in 1000 mg L-1 of neutralized AA may be useful. ?? 2006 Blackwell Publishing Ltd.

Wheat bran particle size influence on phytochemical extractability and antioxidant properties.

PubMed

Brewer, Lauren Renee; Kubola, Jittawan; Siriamornpun, Sirithon; Herald, Thomas J; Shi, Yong-Cheng

2014-01-01

It is unknown if particle size plays a role in extracting health promoting compounds in wheat bran because the extraction of antioxidant and phenolic compounds with particle size reduction has not been well documented. In this study, unmilled whole bran (coarse treatment) was compared to whole bran milled to medium and fine treatments from the same wheat bran. Antioxidant properties (capacity, ability, power), carotenoids and phenolic compounds (phenolic acids, flavonoids, anthocyanins) were measured and compared. The ability of whole bran fractions of differing particle size distributions to inhibit free radicals was assessed using four in vitro models, namely, diphenylpicrylhydrazyl radical-scavenging activity, ferric reducing/antioxidant power (FRAP) assay, oxygen radical absorbance capacity (ORAC), and total antioxidant capacity. Significant differences in phytochemical concentrations and antioxidant properties were observed between whole bran fractions of reduced particle size distribution for some assays. The coarse treatment exhibited significantly higher antioxidant properties compared to the fine treatment; except for the ORAC value, in which coarse was significantly lower. For soluble and bound extractions, the coarse treatment was comparatively higher in total antioxidant capacity (426.72 mg ascorbic acid eq./g) and FRAP value (53.04 μmol FeSO4/g) than bran milled to the finer treatment (314.55 ascorbic acid eq./g and 40.84 μmol FeSO4/g, respectively). Likewise, the fine treatment was higher in phenolic acid (7.36 mg FAE/g), flavonoid (206.74 μg catechin/g), anthocyanin (63.0 μg/g), and carotenoid contents (beta carotene, 14.25 μg/100 g; zeaxanthin, 35.21 μg/100 g; lutein 174.59 μg/100 g) as compared to the coarse treatment. An increase of surface area to mass increased the ORAC value by over 80%. With reduction in particle size, there was a significant increase in extracted anthocyanins, carotenoids and ORAC value. Particle size does effect the extraction of phytochemicals. Copyright © 2013 Elsevier Ltd. All rights reserved.

An efficient synthesis of tetramic acid derivatives with extended conjugation from L-Ascorbic Acid

PubMed Central

Singh, Biswajit K; Bisht, Surendra S; Tripathi, Rama P

2006-01-01

Background Tetramic acids with polyenyl substituents are an important class of compounds in medicinal chemistry. Both solid and solution phase syntheses of such molecules have been reported recently. Thiolactomycin, a clinical candidate for treatment of tuberculosis has led to further explorations in this class. We have recently developed an efficient synthesis of tetramic acids derivatives from L- ascorbic acid. In continuation of this work, we have synthesised dienyl tetramic acid derivatives. Results 5,6-O-Isopropylidene-ascorbic acid on reaction with DBU led to the formation of tetronolactonyl allyl alcohol, which on oxidation with pyridinium chlorochromate gave the respective tetranolactonyl allylic aldehydes. Wittig olefination followed by reaction of the resulting tetranolactonyl dienyl esters with different amines resulted in the respective 5-hydroxy lactams. Subsequent dehydration of the hydroxy lactams with p-toluene sulphonic acid afforded the dienyl tetramic acid derivatives. All reactions were performed at ambient temperature and the yields are good. Conclusion An efficient and practical method for the synthesis of dienyl tetramic acid derivatives from inexpensive and easily accessible ascorbic acid has been developed. The compounds bear structural similarities to the tetramic acid based polyenic antibiotics and thus this method offers a new and short route for the synthesis of tetramic acid derivatives of biological significance. PMID:17147830

An efficient synthesis of tetramic acid derivatives with extended conjugation from L-ascorbic acid.

PubMed

Singh, Biswajit K; Bisht, Surendra S; Tripathi, Rama P

2006-12-06

Tetramic acids with polyenyl substituents are an important class of compounds in medicinal chemistry. Both solid and solution phase syntheses of such molecules have been reported recently. Thiolactomycin, a clinical candidate for treatment of tuberculosis has led to further explorations in this class. We have recently developed an efficient synthesis of tetramic acids derivatives from L-ascorbic acid. In continuation of this work, we have synthesised dienyl tetramic acid derivatives. 5,6-O-isopropylidene-ascorbic acid on reaction with DBU led to the formation of tetronolactonyl allyl alcohol, which on oxidation with pyridinium chlorochromate gave the respective tetranolactonyl allylic aldehydes. Wittig olefination followed by reaction of the resulting tetranolactonyl dienyl esters with different amines resulted in the respective 5-hydroxy lactams. Subsequent dehydration of the hydroxy lactams with p-toluene sulphonic acid afforded the dienyl tetramic acid derivatives. All reactions were performed at ambient temperature and the yields are good. An efficient and practical method for the synthesis of dienyl tetramic acid derivatives from inexpensive and easily accessible ascorbic acid has been developed. The compounds bear structural similarities to the tetramic acid based polyenic antibiotics and thus this method offers a new and short route for the synthesis of tetramic acid derivatives of biological significance.

Formulation with ascorbic acid and sucrose modulates catechin bioavailability from green tea

PubMed Central

Peters, Catrina M.; Green, Rodney J.; Janle, Elsa M.; Ferruzzi, Mario G.

2009-01-01

In order to investigate the impact of common food ingredients on catechin absorption, green tea (GT) extract (50 mg) was formulated plain, with sucrose (GT+S), with ascorbic acid (GT+AA) and with sucrose and ascorbic acid (GT+S+AA). Bioavailability and bioaccessibility were assessed in Sprague Dawley rats and an in vitro digestion/Caco-2 cell model respectively. Absorption of epigallocatechin (EGC) and epigallocatechin gallate (EGCG) was significantly (P<0.05) enhanced in GT+S+AA formulations (AUC0-6h= 3237.0 and 181.8 pmol*h/L plasma respectively) relative to GT control (AUC0-6h = 1304.1 and 61.0 pmol*h/L plasma respectively). In vitro digestive recovery was higher for EGC and epicatechin (EC) (∼51-53%) relative to EGCG and epicatechin gallate (ECG) (< 20%) and was modestly enhanced in GT+S and GT+S+AA formulations. Accumulation of EGC, EGCG and ECG by Caco-2 cells was significantly (P<0.05) higher from GT+S+AA compared to other formulations while retention of catechins was enhanced in presence of ascorbic acid. These data suggest that formulation with sucrose and ascorbic acid may improve catechin bioavailability by enhancing bioaccessibility and intestinal uptake from tea. PMID:20161530

Bioaccessibility of tocopherols, carotenoids, and ascorbic acid from milk- and soy-based fruit beverages: influence of food matrix and processing.

PubMed

Cilla, Antonio; Alegría, Amparo; de Ancos, Begoña; Sánchez-Moreno, Concepción; Cano, M Pilar; Plaza, Lucía; Clemente, Gonzalo; Lagarda, María J; Barberá, Reyes

2012-07-25

A study was made of the effect of high-pressure processing (HPP) and thermal treatment (TT) on plant bioactive compounds (tocopherols, carotenoids, and ascorbic acid) in 12 fruit juice-milk beverages and of how the food matrix [whole milk (JW), skimmed milk (JS), and soy milk (JSy)] modulates their bioaccessibility (%). HPP (400 MPa/40 °C/5 min) produced a significant decrease in carotenoid and ascorbic acid bioaccessibility in all three beverages and maintained the bioaccessibility of tocopherols in JW and JS while decreasing it in JSy. TT (90 °C/30 s) produced a significant decrease in tocopherol and carotenoid bioaccessibility in all three beverages and increased the bioaccessibility of ascorbic acid. With regard to the food matrix, α-tocopherol and ascorbic acid bioaccessibility was greatest in JW beverages and lowest in JSy beverages, whereas no significant differences were found among the three beverages in terms of carotenoid bioaccessibility. HPP-treated samples showed higher tocopherol and carotenoid bioaccessibility than TT-treated samples, thus indicating that HPP combined with a milk matrix positively modulates the bioaccessibility of certain types of bioactive components of food, mainly those of a lipophilic nature.

Synthesis, characterization, and the antioxidant activity of N,N,N-trimethyl chitosan salts.

PubMed

Zhang, Jingjing; Tan, Wenqiang; Wang, Gang; Yin, Xiuli; Li, Qing; Dong, Fang; Guo, Zhanyong

2018-06-05

Chitosan, possessing excellent properties, has been drawing broad attention. For the further utilization of chitosan, chemical modification is performed in improving its water solubility and the bioactivities. In the current study, four N,N,N-trimethyl chitosan salts, including N,N,N-trimethyl chitosan citrate (TMCSCi), N,N,N-trimethyl chitosan acetylsalicylate (TMCSAc), N,N,N-trimethyl chitosan ascorbate (TMCSAs), and N,N,N-trimethyl chitosan gallate (TMCSGa), were prepared via N,N,N-trimethyl chitosan iodide (TMCSI). The as-prepared products were characterized by FT-IR and 1 H NMR. Meanwhile, the degrees of substitution were calculated by elemental analysis results. Furthermore, scavenging activities (against DPPH radicals and superoxide radicals) test and reducing power test were selected to evaluate the antioxidant property of N,N,N-trimethyl chitosan salts in vitro. The results indicated that TMCSAs and TMCSGa displayed excellent activity, probably due to the enhancement of ascorbate and gallate in antioxidant activity. However, because of the weak antioxidant property of citrate and acetylsalicylate, the activity was lower for TMCSCi and TMCSAc. For example, in the DPPH radicals scavenging assay, the scavenging rates of chitosan, TMCSI, TMCSCi, TMCSAc, TMCSAs, and TMCSGa were 25.22, 84.11, 6.90, 2.70, 94.92, and 96.75% at 0.4 mg/mL, respectively. Generally, TMCSAs and TMCSGa could be regarded as a potential source of antioxidants. Copyright © 2017. Published by Elsevier B.V.

The Oxidation of Ascorbic Acid by Hexacyanoferrate(III) Ion in Acidic Aqueous Media.

ERIC Educational Resources Information Center

Martins, Luis J. A.; da Costa, J. Barbosa

1988-01-01

Describes a kinetic and mechanistic investigation of ascorbic acid by a substitution-inert complex in acidic medium suitable for the undergraduate level. Discusses obtaining the second order rate constant for the rate determining step at a given temperature and comparison with the value predicted on the basis of the Marcus cross-relation. (CW)

Purification and characterization of an antioxidant glycoprotein from the hydrolysate of Mustelus griseus.

PubMed

Li, Zhongrui; Wang, Bin; Chi, Changfeng; Gong, Yandan; Tang, Jiajia; Luo, Hongyu

2013-01-01

An antioxidant glycoprotein (Fraction AIV-2) with molecular weight of 27.2 kDa was purified from the ethanol-soluble protein hydrolysate of Mustelus griseus muscle. The 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical scavenging activity of Fraction AIV-2 reached up to 96.73±2.33% and was higher than that of ascorbic acid at the concentration of 5.0mg/mL. Total protein and carbohydrate contents of Fraction AIV-2 were 62.65±0.63% and 33.49±1.60%, respectively. Seventeen amino acids were identified in Fraction AIV-2, most of which are serine. GC-MS analysis showed that Fraction AIV-2 was composed of fucose, arabinose, galactose, glucose and mannose with the ratio of 1.00:1.53:7.27:9.07:2.09. The FT-IR spectrum of Fraction AIV-2 showed typical characteristics of polysaccharide and protein. For Fraction AIV-2, the changes of ultraviolet absorption curve, amino acid composition after the β-elimination reaction and its deglycosylation with the treatment of N-glycosidase F suggested that both O-glycosidic and N-glycosidic bonds were involved in the polysaccharide and protein moieties. Copyright © 2012 Elsevier B.V. All rights reserved.

Transcriptome mining and in silico structural and functional analysis of ascorbic acid and tartaric acid biosynthesis pathway enzymes in rose-scanted geranium.

PubMed

Narnoliya, Lokesh K; Sangwan, Rajender S; Singh, Sudhir P

2018-06-01

Rose-scented geranium (Pelargonium sp.) is widely known as aromatic and medicinal herb, accumulating specialized metabolites of high economic importance, such as essential oils, ascorbic acid, and tartaric acid. Ascorbic acid and tartaric acid are multifunctional metabolites of human value to be used as vital antioxidants and flavor enhancing agents in food products. No information is available related to the structural and functional properties of the enzymes involved in ascorbic acid and tartaric acid biosynthesis in rose-scented geranium. In the present study, transcriptome mining was done to identify full-length genes, followed by their bioinformatic and molecular modeling investigations and understanding of in silico structural and functional properties of these enzymes. Evolutionary conserved domains were identified in the pathway enzymes. In silico physicochemical characterization of the catalytic enzymes revealed isoelectric point (pI), instability index, aliphatic index, and grand average hydropathy (GRAVY) values of the enzymes. Secondary structural prediction revealed abundant proportion of alpha helix and random coil confirmations in the pathway enzymes. Three-dimensional homology models were developed for these enzymes. The predicted structures showed significant structural similarity with their respective templates in root mean square deviation analysis. Ramachandran plot analysis of the modeled enzymes revealed that more than 84% of the amino acid residues were within the favored regions. Further, functionally important residues were identified corresponding to catalytic sites located in the enzymes. To, our best knowledge, this is the first report which provides a foundation on functional annotation and structural determination of ascorbic acid and tartaric acid pathway enzymes in rose-scanted geranium.

Coordination chemistry of vitamin C. Part I. Interaction of L-ascorbic acid with alkaline earth metal ions in the crystalline solid and aqueous solution.

PubMed

Tajmir-Riahi, H A

1990-10-01

The interaction of L-ascorbic acid with alkaline earth metal ions has been investigated in aqueous solution at pH 6-7. The solid salts of the type Mg(L-ascorbate)2.4H2O, Ca(L-ascorbate)2.2H2O, Sr(L-ascorbate)2.2H2O and Ba(L-ascorbate)2.2H2O were isolated and characterized by means of 13C NMR and FT-IR spectroscopy. Spectroscopic and other evidence suggested that in aqueous solution, the binding of the alkaline earth metal ions is through the O-3 atom of the ascorbate anion, while in the solid state the binding of the Mg(II) is different from those of the other alkaline earth metal ion salts. The Mg(II) ion binds to the O-3, O-1 atom of the two ascorbate anions and to two H2O molecules, while the eight-coordination around the Ca(II), Sr(II), and Ba(II) ions would be completed by the coordination of three acid anions, through O-5, O-6 of the first, O-3, O-5, O-6 of the second and O-1 of the third anion as well as to two H2O molecules. The structural properties of the alkaline earth metal-ascorbate salts are different in the solid and aqueous solution.

Effects of vitamins A and D on the biosynthesis of L-ascorbic acid by rat-liver microsomes

PubMed Central

Ghosh, N. C.; Chatterjee, Ipsita; Chatterjee, G. C.

1965-01-01

1. The synthesis of l-ascorbic acid from either d-glucuronolactone or l-gulonolactone by liver microsomes of rats is decreased under conditions of hypervitaminosis A; under hypervitaminosis D the synthesis from d-glucuronolactone is increased and that from l-gulonolactone is not affected. 2. The microsomal conversion of l-gulonolactone into l-ascorbic acid is impaired in liver tissues of rats made deficient with respect to either vitamin A or vitamin D when compared with the controls maintained on stock diet. PMID:16749110

The changes in the electronic spectra of ascorbic acid induced by laser radiation

NASA Astrophysics Data System (ADS)

Danyaeva, J. S.; Kutsenko, S. A.

2018-04-01

The results of research the changes in the absorption spectra of aqueous solutions of ascorbic acid under the influence of laser radiation are presented. The solutions were irradiated with the radiation of semiconductor lasers with wavelengths of 408 and 532 nm, YAG: Nd3+ laser with a wavelength of 1064 nm and a nitrogen laser with a wavelength of 337.1 nm. The photoinduced changes in the spectrum are revealed, which indicate the breakage of π -> π bonds in the molecule of ascorbic acid during its destruction.

Morphological Diversity in Crystal Growth of l-Ascorbic Acid Dissolved in Methanol

NASA Astrophysics Data System (ADS)

Ito, Miho; Izui, Machiko; Yamazaki, Yoshihiro; Matsushita, Mitsugu

2003-06-01

Morphological diagram with respect to crystal growth of l-ascorbic acid (C6H8O6; so-called vitamin C) from methanol solution on a flat glass dish is presented. Varying humidity and initial concentration of l-ascorbic acid in methanol solution, the following three distinct kinds of growing patterns have been observed: homogeneous disk, concentric ring and dendrite. In addition, in higher concentration clearly faceted small single crystals grow in any humidity less than 90%. Crossovers from one pattern to another were observed, too.

Cupric ion reducing antioxidant capacity assay for antioxidants in human serum and for hydroxyl radical scavengers.

PubMed

Apak, Reşat; Güçlü, Kubilay; Ozyürek, Mustafa; Bektaşoğlu, Burcu; Bener, Mustafa

2010-01-01

Tests measuring the combined antioxidant effect of the nonenzymatic defenses in biological fluids may be useful in providing an index of the organism's capability to counteract reactive species known as pro-oxidants, resist oxidative damage, and combat oxidative stress-related diseases. The selected chromogenic redox reagent for the assay of human serum should be easily accessible, stable, selective, and respond to all types of biologically important antioxidants such as ascorbic acid, alpha-tocopherol, beta-carotene, reduced glutathione (GSH), uric acid, and bilirubin, regardless of chemical type or hydrophilicity. Our recently developed cupric reducing antioxidant capacity (CUPRAC) spectrophotometric method for a number of polyphenols and flavonoids using the copper(II)-neocuproine reagent in ammonium acetate buffer is now applied to a complete series of plasma antioxidants for the assay of total antioxidant capacity of serum, and the resulting absorbance at 450 nm is recorded either directly (e.g., for ascorbic acid, alpha-tocopherol, and glutathione) or after incubation at 50 degrees C for 20 min (e.g., for uric acid, bilirubin, and albumin), quantitation being made by means of a calibration curve. The lipophilic antioxidants, alpha-tocopherol and beta-carotene, are assayed in dichloromethane. Lipophilic antioxidants of serum are extracted with n-hexane from an ethanolic solution of serum subjected to centrifugation. Hydrophilic antioxidants of serum are assayed in the centrifugate after perchloric acid precipitation of proteins. The CUPRAC molar absorptivities, linear ranges, and TEAC (trolox equivalent antioxidant capacity) coefficients of the serum antioxidants are established, and the results are evaluated in comparison with the findings of the ABTS/TEAC reference method. The intra- and inter-assay coefficients of variation (CVs) are 0.7 and 1.5%, respectively, for serum. The CUPRAC assay proved to be efficient for glutathione and thiol-type antioxidants, for which the FRAP (ferric reducing antioxidant potency) test is basically nonresponsive. The additivity of absorbances of all the tested antioxidants confirmed that antioxidants in the CUPRAC test do not chemically interact among each other so as to cause an intensification or quenching of the theoretically expected absorbance, and that a total antioxidant capacity (TAC) assay of serum is possible. As a distinct advantage over other electron-transfer based assays (e.g., Folin, FRAP, ABTS, DPPH), CUPRAC is superior in regard to its realistic pH close to the physiological pH, favorable redox potential, accessibility and stability of reagents, and applicability to lipophilic antioxidants as well as hydrophilic ones. The CUPRAC procedure can also assay hydroxyl radicals, being the most reactive oxygen species (ROS). As a more convenient, efficient, and less costly alternative to HPLC/electrochemical detection techniques and to the nonspecific, low-yield TBARS test, we use p-aminobenzoate, 2,4- and 3,5-dimethoxybenzoate probes for detecting hydroxyl radicals generated from an equivalent mixture of [Fe(II)+EDTA] with hydrogen peroxide. The produced hydroxyl radicals attack both the probe and the water-soluble antioxidants in 37 degrees C-incubated solutions for 2 h. The CUPRAC absorbance of the ethylacetate extract due to the reduction of Cu(II)-neocuproine reagent by the hydroxylated probe decreases in the presence of (.)OH scavengers, the difference being proportional to the scavenging ability of the tested compound. The developed method is less lengthy, more specific, and of a higher yield than the classical TBARS assay.

Total Phenol Content and In Vitro Antioxidant Potential of Helicanthus elastica (Desr.) Danser-A Less-explored Indian Mango Mistletoe

PubMed Central

Sunil Kumar, Koppala Narayana; Saraswathy, Ariyamuthu; Amerjothy, Swaminathan; Susan, Thomas; Ravishankar, Basaviah

2014-01-01

Natural products are an important source of antioxidant molecules like tannins, phenolic compounds, flavonoids, etc., Helicanthus elastica (Desr.) Danser (Loranthaceae) is one such plant belonging to the category of mistletoe, and grows commonly on the mango trees in India. In the present study, an attempt has been made to assess the antioxidant properties of the plant. Ethanol extract of H. elastica growing on mango tree was studied using different in vitro models. Shade-dried whole plant material was extracted with ethanol by cold percolation. Fifty milligrams of the alcohol extract of H. elastica was weighed and dissolved in 10 ml of methanol. The resultant 5 mg/ml solution was suitably diluted to obtain different concentrations. Total phenol content, reducing power assay, and scavenging of free radicals like nitric oxide, hydroxyl, hydrogen peroxide, and 1,1-diphenyl-2-picrylhydrazyl were studied by standardized in vitro chemical methods using ascorbic acid as the standard. The total phenol content of the plant was found to be 1.89% w/w. The extract showed good reducing power as well as scavenging of free radicals (nitric oxide, hydroxyl, superoxide anion, and hydrogen peroxide) at concentrations ranging from 5 to 100 μg/ml. The study revealed the antioxidant potential of H. elastica. PMID:25379473

Optimized Extraction of Polysaccharides from Grateloupia livida (Harv.) Yamada and Biological Activities.

PubMed

Ye, Danyan; Jiang, Zebin; Zheng, Fuchun; Wang, Hongmei; Zhang, Yanmei; Gao, Fenfei; Chen, Peihong; Chen, Yicun; Shi, Ganggang

2015-09-16

Polysaccharides from Grateloupia livida (Harv.) Yamada (GL) were extracted by a heating circumfluence method. Single-factor experiments were performed for the three parameters: extraction time (X₁), extraction temperature (X₂) and the ratio of water to raw material (X₃) and their test range. From preliminary experimental results, one type of the response surface methodology, the Box-Behnken design was applied for the optimizing polysaccharide extraction conditions. The experimental data obtained were fitted to a second-order polynomial equation. The optimal conditions were extraction time 5 h, extraction temperature 100 °C and ratio of water to raw material 70 mL/g. Under these conditions, the experimental yield was 39.22% ± 0.09%, which well matched the predicted value (39.25%), with 0.9774 coefficient of determination (R²). GL polysaccharides had scavenging activities for DPPH and hydroxyl radicals in vitro. The scavenging rates for both radicals peaked at 20 mg/mL GL concentration. However, the positive standard, VC (ascorbic acid), possessed stronger antioxidant activities than GL polysaccharides. Furthermore, the anticancer activity of GL polysaccharides on HepG2 cell proliferation increased dose- and time-dependently, but the positive standard, 5-fluorouracil (5-fu) showed more significant anticancer activity in this study. Overall, GL polysaccharides may have potential applications in the medical and food industries.

Antioxidant Properties and Cardioprotective Mechanism of Malaysian Propolis in Rats

PubMed Central

Ahmed, Romana; Hossen, Md. Sakib; Ahmmed, Istiyak; Rumpa, Nur-E-Noushin; Sulaiman, Siti Amrah

2017-01-01

Propolis contains high concentrations of polyphenols, flavonoids, tannins, ascorbic acid, and reducing sugars and proteins. Malaysian Propolis (MP) has been reported to exhibit high 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical-scavenging activity and ferric reducing antioxidant power (FRAP) values. Herein, we report the antioxidant properties and cardioprotective properties of MP in isoproterenol- (ISO-) induced myocardial infarction in rats. Male Wistar rats (n = 32) were pretreated orally with an ethanol extract of MP (100 mg/kg/day) for 30 consecutive days. Subcutaneous injection of ISO (85 mg/kg in saline) for two consecutive days caused a significant increase in serum cardiac marker enzymes and cardiac troponin I levels and altered serum lipid profiles. In addition significantly increased lipid peroxides and decreased activities of cellular antioxidant defense enzymes were observed in the myocardium. However, pretreatment of ischemic rats with MP ameliorated the biochemical parameters, indicating the protective effect of MP against ISO-induced ischemia in rats. Histopathological findings obtained for the myocardium further confirmed the biochemical findings. It is concluded that MP exhibits cardioprotective activity against ISO-induced oxidative stress through its direct cytotoxic radical-scavenging activities. It is also plausible that MP contributed to endogenous antioxidant enzyme activity via inhibition of lipid peroxidation. PMID:28261310

Antioxidant activity of Syzygium cumini leaf gall extracts

PubMed Central

Eshwarappa, Ravi Shankara Birur; Iyer, Raman Shanthi; Subbaramaiah, Sundara Rajan; Richard, S Austin; Dhananjaya, Bhadrapura Lakkappa

2014-01-01

Introduction: Free radicals are implicated in several metabolic diseases and the medicinal properties of plants have been explored for their potent antioxidant activities to counteract metabolic disorders. This research highlights the chemical composition and antioxidant potential of leaf gall extracts (aqueous and methanol) of Syzygium cumini (S. cumini), which have been extensively used in traditional medications to treat various metabolic diseases. Methods: The antioxidant activities of leaf gall extracts were examined using diphenylpicrylhydrazyl (DPPH), nitric oxide scavenging, hydroxyl scavenging and ferric reducing power (FRAP) methods. Results: In all the methods, the methanolic extract showed higher antioxidant potential than the standard ascorbic acid. The presence of phenolics, flavonoids, phytosterols, terpenoids, and reducing sugars was identified in both the extracts. When compared, the methanol extract had the highest total phenolic and flavonoid contents at 474±2.2 mg of GAE/g d.w and 668±1.4 mg of QUE/g d.w, respectively. The significant high antioxidant activity can be positively correlated to the high content of total polyphenols/flavonoids of the methanol extract. Conclusion: The present study confirms the folklore use of S. cumini leaves gall extracts as a natural antioxidant and justifies its ethnobotanical use. Further, the result of antioxidant properties encourages the use of S. cumini leaf gall extracts for medicinal health, functional food and nutraceuticals applications. PMID:25035854

A novel method for the determination of ascorbic acid and antioxidant capacity in Opuntia ficus indica using in vivo microdialysis.

PubMed

Pretti, L; Bazzu, G; Serra, P A; Nieddu, G

2014-03-15

A simple and rapid method was developed for in vivo simultaneous determination of ascorbic-acid and antioxidant capacity in microdialysates from cladodes of Opuntia ficus-indica (L.) Miller. The method is verified in water-stressed plants, as compared with a well-watered test controls. The microdialysis probe construction and insertion procedure was specifically developed to minimise the tissue trauma of the plant and to obtain optimal dialysis performance. Microdialysis was performed using a flow rate of 3 μL/min and the samples were analysed by HPLC coupled to electrochemical detection of ascorbic-acid and DPPH-determined antioxidant capacity. Our data indicate exponential decay of the concentrations of the analysed compounds as a function of microdialysis sampling time. Water-stressed Opuntia show decreased ascorbic acid levels and increased the others antioxidants. Copyright © 2013 Elsevier Ltd. All rights reserved.

Effect of antacid and ascorbic acid on serum salicylate concentration.

PubMed

Hansten, P D; Hayton, W L

1980-01-01

To determine the effect of antacid or ascorbic acid administration on plateau serum salicylate concentrations, nine healthy subjects were given each of the following treatments by balanced block design: choline salicylate (equivalent to 3.76 or 5.62 Gm/day of aspirin); choline salicylate plus magnesium-aluminum hydroxide (120 ml/day); or choline salicylate plus ascorbic acid (3 Gm/day). In subjects developing a control serum salicylate level above 10 mg/dl, antacid administration produced a decrease in serum salicylate level (mean 19.8 mg/dl vs. 15.8 mg/dl) (P less than 0.01). Ascorbic acid administration was not associated with a significant change in serum salicylate. The reduction in serum salicylate following antacid appears to be due to antacid-induced alkalinization of the urine with resultant increase in renal salicylate clearance. Antacid administration should be considered a potential cause of altered serum salicylate concentration in patients receiving large doses of salicylate.

Effect of curcumin against oxidation of biomolecules by hydroxyl radicals.

PubMed

Borra, Sai Krishna; Mahendra, Jaideep; Gurumurthy, Prema; Jayamathi; Iqbal, Shabeer S; Mahendra, Little

2014-10-01

Among various reactive oxygen species, hydroxyl radicals have the strongest chemical activity, which can damage a wide range of essential biomolecules such as lipids, proteins, and DNA. The objective of this study was to investigate the beneficial effects of curcumin on prevention of oxidative damage of biomolecules by hydroxyl radicals generated in in vitro by a Fenton like reaction. We have incubated the serum, plasma and whole blood with H2O2/Cu2+/ Ascorbic acid system for 4 hours at 37 0C and observed the oxidation of biomolecules like albumin, lipids, proteins and DNA. Curcumin at the concentrations of 50,100 and 200 μmoles, prevented the formation of ischemia modified albumin, MDA, protein carbonyls, oxidized DNA and increased the total antioxidant levels and GSH significantly. These observations suggest the hydroxyl radical scavenging potentials of curcumin and protective actions to prevent the oxidation of biomolecules by hydroxyl radicals.

Improvement of Ultrasonic Disinfection Power Using TiO2 Photocatalyst

NASA Astrophysics Data System (ADS)

Dadjour, Mahmoud Farshbaf; Ogino, Chiaki; Matsumura, Susumu; Nakamura, Shinichi; Shimizu, Nobuaki

2005-03-01

The disinfection power of an ultrasonic system was enhanced using TiO2-photocatalyst in the irradiating solutions. Cultures of Legionella were used in the irradiation system with and without TiO2. A significant decrease in the concentration of viable cells was observed during irradiation in the presence of TiO2. The rate of cell killing was higher in the presence of TiO2 than it was with Al2O3, and was proportional to the amount of TiO2 used in the irradiating samples. There was no significant effect of cell concentration on the rate of cell killing in the range of 103 to 107 CFU/ml. Addition of OH radical scavengers such as glutathione, ascorbic acid and histidine to the irradiating solutions reduced the rate of disinfection, thus indicating the primary role of OH radicals in this process.

Synthesis, structurale elucidation and antioxidant study of Ortho-substituted N,N’-bis(benzamidothiocarbonyl)hydrazine derivatives

NASA Astrophysics Data System (ADS)

Firdausiah, Syadza; Hasbullah, S. A.; Yamin, B. M.

2018-03-01

Some bis(thiourea) compounds have been reported to posses excellent performance in pharmaceutical and environmental fields because of their ability to form chelating complexes with various anions and metal ions. Structurally for carbonyl thiourea derivatives, to become a chelating agent, it must adopt cis-configuration. In the present study, four new bis(thiourea) derivatives namely N,N’-bis(o-fluorobenzamidothiocarbonyl)hydrazine (1), N,N’- bis(o-chloro-benzamidothiocarbonyl)hydrazine (2), N,N’-bis(o-nitrobenzamidothiocarbonyl)-hydrazine (3), and N,N’-bis(o-methylbenzamidothiocarbonyl)hydrazine (4) were successfully synthesized and characterized by CHNS microelemental analysis, FTIR, UV-Vis, and 1H and 13C NMR spectroscopy. However chemical crystallography study showed that both thiourea moieties in compound (2) and (3) adopt trans geometry. Therefore they are potential monodentate ligand with two active moieties. DPPH radical scavenging experiment showed that compound (1), (2), and (4) exhibited higher antioxidant activity than ascorbic acid (Vitamin C).

Hypoglycemic effect of ethanolic extract of Musa sapientum on alloxan induced diabetes mellitus in rats and its relation with antioxidant potential.

PubMed

Dhanabal, S P; Sureshkumar, M; Ramanathan, M; Suresh, B

2005-01-01

The antihyperglycemic effect of ethanolic extract of flowers of Musa sapientum (Musaceae), a herb (used in Indian folklore medicine for the treatment of diabetes mellitus) in alloxan induced diabetic rats. Oral administration of the ethanolic extract showed significant (p < 0.001) blood glucose lowering effect at 200 mg/kg in alloxan induced diabetic rats (120 mg/kg, i.p.) and the extract was also found to significantly (p < 0.001) scavenge oxygen free radicals, viz., superoxide dismutase (SOD), catalase (CAT) and also protein, malondialdehyde and ascorbic acid in vivo. Musa sapientum induced blood sugar reduction may be due to possible inhibition of free radicals and subsequent inhibition of tissue damage induced by alloxan. The antidiabetic activity observed in this plant may be attributed to the presence of flavonoids, alkaloids, steroid and glycoside principles.

Antiurease and anti-oxidant activity of Vaccinium macrocarpon fruit.

PubMed

Noreen, Shabana; Shaheen, Ghazala; Akram, Muhammad; Rashid, Abid; Shah, Syed Muhammad Ali

2016-07-01

The objective of present study was to evaluate the antiurease and anti-oxidant activity of Vaccinium macrocarpon fruit. The parent extract was ethanolic extract while its sub fractions were prepared in n-hexane, chloroform and n-butanol. The method based on scavenging activity and reduction capability of 1, 1-diphenyl-2-picrylhydrazyl radical (DPPH). N-butanol fraction was the most effective antioxidant with 87.0±1.15 activity but the activity was less than ascorbic acid i.e. 93.74±0.12. Highly significant urease inhibition was shown by crude ethanolic extract (71.00±0.2a) with IC50 (392.66±2.1) followed by aqueous fraction (68.00±0.5e) with IC50 (159.83±2.8). The results of crude ethanolic extract and aqueous extracts were highly significant (p<0.05) than standard Thiourea. Present study showed that Vaccinium macrocarpon exhibits potent antiurease and antioxidant activities.

In Vitro Antioxidant-Activity Evaluation of Gallic-Acid-Grafted Chitosan Conjugate Synthesized by Free-Radical-Induced Grafting Method.

PubMed

Hu, Qiaobin; Wang, Taoran; Zhou, Mingyong; Xue, Jingyi; Luo, Yangchao

2016-07-27

The major objective of this work was to develop a green and facile process to prepare gallic acid-chitosan conjugate and comprehensively evaluate the physicochemical properties and biological activities of an as-prepared water-soluble chitosan derivative. A free-radical-induced grafting approach using an ascorbic acid-hydrogen peroxide redox pair was adopted. The obtained conjugate was characterized by Fourier transform infrared spectroscopy, UV-vis, X-ray diffraction, and pKa analysis. The antioxidant activities were evaluated by 2,2-diphenyl-1-picrylhydrazyl (DPPH), 2,2'-azino-bis(3-ethylbenzothiazoline-6)-sulphonic acid (ABTS), reducing power, and oxygen-radical antioxidant-capacity assays. The results showed that the mass ratio of gallic acid to chitosan played a vital role in determining the grafting degree and ζ potential of the conjugates, with the ratio of 0.5:1 being the optimal ratio that resulted in the highest grafting degree. The antioxidant assays demonstrated that conjugation significantly improved the antioxidant activities, being dramatically higher than that of free chitosan. It was notable that the DPPH- and ABTS-scavenging activities of conjugate at 0.4 mg/mL reached the same level as the free gallic acid at the equivalent concentration. Our study demonstrated a green and facile synthesis approach to preparing a novel water-soluble chitosan derivative that may have promising potentials in the food industry.

Protein glycation inhibitory activity and antioxidant capacity of clove extract.

PubMed

Suantawee, Tanyawan; Wesarachanon, Krittaporn; Anantsuphasak, Kanokphat; Daenphetploy, Tanuch; Thien-Ngern, Sroshin; Thilavech, Thavaree; Pasukamonset, Porntip; Ngamukote, Sathaporn; Adisakwattana, Sirichai

2015-06-01

Syzygium aromaticum (L.) (clove) is one of the most widely cultivated spices in many tropical countries. The aim of this study was to determine the phytochemical content, the antioxidant properties and the antiglycation properties of aqueous extract of clove against fructose-mediated protein glycation and oxidation. The result showed that the content of total phenolics and flavonoids in clove extract was 239.58 ± 0.70 mg gallic acid equivalents/g dried extract and 65.67 ± 0.01 mg catechin equivalents/g dried extract, respectively. In addition, clove exhibited antioxidant properties including DPPH radical scavenging activity (IC50 = 0.29 ± 0.01 mg/ml), Trolox equivalent antioxidant capacity (4.69 ± 0.03 μmol Trolox equivalents/mg dried extract), ferric reducing antioxidant power (20.55 ± 0.11 μmol ascorbic acid equivalents/mg dried extract), Oxygen radical absorbance capacity (31.12 ± 0.21 μmol Trolox equivalents/mg dried extract), hydroxyl radical scavenging activity (0.15 ± 0.04 mg Trolox equivalents/mg dried extract), and superoxide radical scavenging activity (18.82 ± 0.50 mg Trolox equivalents/mg dried extract). The aqueous extract of clove (0.25-1.00 mg/ml) significantly inhibited the formation of fluorescent advanced glycation end products (AGEs) and non-fluorescent AGEs (N(ɛ)-(carboxymethyl) lysine (CML)) in glycated BSA during 4 weeks of incubation. The extract also markedly prevented oxidation-induced protein damage by decreasing protein carbonyl formation and protecting against the loss of protein thiol group. These results clearly demonstrated that a polyphenol enriched clove extract, owing to its antioxidant, was capable to inhibit the formation of AGEs and protein glycation. The findings might lead to the possibility of using the clove extract for targeting diabetic complications.

Vitamin C physiology: the known and the unknown and Goldilocks

PubMed Central

Padayatty, Sebastian J; Levine, Mark

2016-01-01

Vitamin C (Ascorbic Acid), the antiscorbutic vitamin, cannot be synthesized by humans and other primates, and has to be obtained from diet. Ascorbic acid is an electron donor and acts as a cofactor for fifteen mammalian enzymes. Two sodium-dependent transporters are specific for ascorbic acid, and its oxidation product dehydroascorbic acid is transported by glucose transporters. Ascorbic acid is differentially accumulated by most tissues and body fluids. Plasma and tissue vitamin C concentrations are dependent on amount consumed, bioavailability, renal excretion, and utilization. To be biologically meaningful or to be clinically relevant, in vitro and in vivo studies of vitamin C actions have to take into account physiologic concentrations of the vitamin. In this paper, we review vitamin C physiology; the many phenomena involving vitamin C where new knowledge has accrued or where understanding remains limited; raise questions about the vitamin that remain to be answered; and explore lines of investigations that are likely to be fruitful. PMID:26808119

Interchange reaction of disulfides and denaturation of oxytocin by copper(II)/ascorbic acid/O2 system.

PubMed

Inoue, H; Hirobe, M

1987-05-29

The interchange reaction of disulfides was caused by the copper(II)/ascorbic acid/O2 system. The incubation of two symmetric disulfides, L-cystinyl-bis-L-phenylalanine (PP) and L-cystinyl-bis-L-tyrosine (TT), with L-ascorbic acid and CuSO4 in potassium phosphate buffer (pH 7.2, 50 mM) resulted in the formation of an asymmetric disulfide, L-cystinyl-L-phenylalanine-L-tyrosine (PT), and the final ratio of PP:PT:TT was 1:2:1. As the reaction was inhibited by catalase and DMSO only at the initial time, hydroxyl radical generated by the copper(II)/ascorbic acid/O2 system seemed to be responsible for the initiation of the reaction. Oxytocin and insulin were denatured by this system, and catalase and DMSO similarly inhibited these denaturations. As the composition of amino acids was unchanged after the reaction, hydroxyl radical was thought to cause the cleavage and/or interchange reaction of disulfides to denature the peptides.

Ascorbic Acid Efflux and Re-uptake in Endothelial Cells: Maintenance of Intracellular Ascorbate

PubMed Central

May, James M.; Qu, Zhi-chao

2013-01-01

Entry of vitamin C or ascorbate into most tissues requires its movement across the endothelial cell barrier of vessels. If trans-cellular ascorbate movement occurs, then it should be evident as ascorbate efflux from endothelial cells. Cultured EA.926 endothelial cells that had been loaded to about 3.5 mM intracellular ascorbate lost 70–80% of ascorbate to the medium over several hours at 37 °C via a non-saturable process that was insensitive to anion transport inhibitors and thiol reagents. Oxidation of this extracellular ascorbate by ascorbate oxidase or ferricyanide enhanced apparent ascorbate efflux, suggesting that efflux of the vitamin was countered in part by its re-uptake on ascorbate transporters. Although basal ascorbate efflux was not calcium-dependent, increased entry of calcium into the cells enhanced ascorbate release. These results support the hypothesis that ascorbate efflux reflects trans-endothelial cell ascorbate movement out of the blood vessel. PMID:19148707

Ascorbic acid efflux and re-uptake in endothelial cells: maintenance of intracellular ascorbate.

PubMed

May, James M; Qu, Zhi-chao

2009-05-01

Entry of vitamin C or ascorbate into most tissues requires its movement across the endothelial cell barrier of vessels. If trans-cellular ascorbate movement occurs, then it should be evident as ascorbate efflux from endothelial cells. Cultured EA.926 endothelial cells that had been loaded to about 3.5 mM intracellular ascorbate lost 70-80% of ascorbate to the medium over several hours at 37 degrees C via a non-saturable process that was insensitive to anion transport inhibitors and thiol reagents. Oxidation of this extracellular ascorbate by ascorbate oxidase or ferricyanide enhanced apparent ascorbate efflux, suggesting that efflux of the vitamin was countered in part by its re-uptake on ascorbate transporters. Although basal ascorbate efflux was not calcium-dependent, increased entry of calcium into the cells enhanced ascorbate release. These results support the hypothesis that ascorbate efflux reflects trans-endothelial cell ascorbate movement out of the blood vessel.

Impact of ultraviolet radiation treatments on the quality of freshly prepared tomato (Solanum lycopersicum) juice.

PubMed

Bhat, Rajeev

2016-12-15

Impact of ultraviolet (UV-C) radiation treatments (0, 15, 30 and 60min) on freshly extracted tomato juice quality (physicochemical properties, antioxidant activity and microbial load) was evaluated. On exposure to UV-C, level of water activity, total soluble solids, and titratable acidity exhibited non-significant increase up to 30min of exposure time. Regarding colour analysis, L∗ value significantly increased with subsequent decrease in a∗ and b∗ values post UV-C treatments. Clarity, DPPH (1,1-diphenyl-2-picrylhydrazyl) radical scavenging activity and total phenolics content significantly increased, whereas ascorbic acid level significantly reduced at 60min of UV-C exposure time. So also, lycopene content exhibited a non-significant decrease after UV-C treatment. Microbial studies showed reduction in total plate count and total mould counts post UV-C treatment. Overall, UV-C treatment being a physical, non-thermal method of food preservation holds the ability to improve or preserve vital quality parameters in freshly prepared tomato juices, and henceforth possesses high scope for commercial exploration. Copyright © 2016 Elsevier Ltd. All rights reserved.

Impact of ultraviolet radiation treatments on the physicochemical properties, antioxidants, enzyme activity and microbial load in freshly prepared hand pressed strawberry juice.

PubMed

Bhat, Rajeev; Stamminger, Rainer

2015-07-01

Freshly prepared, hand-pressed strawberry fruit juice was exposed to ultraviolet radiation (254 nm) at room temperature (25 ℃ ± 1 ℃) for 15, 30 and 60 min with 0 min serving as control. Results revealed decrease in pH, total soluble solids and titratable acidity, while colour parameters (L*, a* and b* values) and clarity of juice (% transmittance) increased significantly. All the results corresponded to exposure time to ultraviolet radiation. Bioactive compounds (total phenolics, ascorbic acid and anthocyanins) decreased along with a recorded reduction in polyphenol oxidase enzyme and 1,1-diphenyl-2-picryl hydrazyl radical scavenging activities, which were again dependent on exposure time. Results on the microbial studies showed significant reduction by 2-log cycles in aerobic plate count as well as in total yeast and mould counts. Though negative results were observed for certain parameters, this is the first time it was endeavoured to demonstrate the impact of ultraviolet radiation radiation on freshly prepared, hand-pressed strawberries juice. © The Author(s) 2014.

Melatonin treatment attenuates postharvest decay and maintains nutritional quality of strawberry fruits (Fragaria×anannasa cv. Selva) by enhancing GABA shunt activity.

PubMed

Aghdam, Morteza Soleimani; Fard, Javad Rezapour

2017-04-15

Fresh strawberry fruits as perishable commodities have a short postharvest life and are prone to postharvest fungal decay. In this study, the impact of 0, 1, 10, 100 and 1000μmol/L melatonin on attenuating fungal decay and maintaining nutritional quality of strawberry fruits was investigated during storage at 4°C for 12days. Melatonin treatment at 100μmol/L triggered H 2 O 2 accumulation, which result from higher superoxide dismutase (SOD) activity, associated with lower catalase (CAT) and ascorbate peroxidase (APX) activities, leading to fruits with lower decay. Higher H 2 O 2 accumulation was concurrent with higher phenylalanine ammonia lyase (PAL) enzyme activity leading to higher total phenols and anthocyanins accumulation along with higher DPPH scavenging capacity. Also, strawberry fruits treated with melatonin exhibited higher γ-aminobutyric acid transaminase (GABA-T) enzyme activity which ensured sufficient ATP supplying leading to higher unsaturated/saturated fatty acids (unSFA/SFA) ratio. Copyright © 2016 Elsevier Ltd. All rights reserved.

Exploring environment-dependent effects of Pd nanostructures on reactive oxygen species (ROS) using electron spin resonance (ESR) technique: implications for biomedical applications.

PubMed

Wen, Tao; He, Weiwei; Chong, Yu; Liu, Yi; Yin, Jun-Jie; Wu, Xiaochun

2015-10-14

Recently, because of the great advances in tailoring their shape and structure, palladium nanoparticles (Pd NPs) have been receiving increasing attention in biomedical fields apart from their traditional application as industrial catalysts. When considering the potential uses of Pd NPs in biomedicine, their catalytic properties need to be evaluated under physiologically relevant conditions. In this article, we demonstrate that Pd nanostructures (NSs, both commercial Pd NPs and in-house-prepared Au@Pd nanorods) can induce O2 or ˙OH production depending on pH values in the presence of H2O2. We observed that O2 is produced under neutral and alkaline conditions but ˙OH under acidic conditions. We also found that Pd NSs can scavenge superoxide and singlet oxygen, which may provide protection in biological systems. On the other hand, their oxidase-like activity may accelerate the oxidation of ascorbic acid and thus may produce negative biological effects. The presented study will provide useful guidance for designing noble metal nanostructures with desired catalytic and biological properties in biomedical applications.

Antioxidant properties of methanol extract and its solvent fractions obtained from selected Indian red seaweeds.

PubMed

Ganesan, P; Kumar, Chandini S; Bhaskar, N

2008-05-01

In vitro antioxidant activities of three selected Indian red seaweeds - viz., Euchema kappaphycus, Gracilaria edulis and Acanthophora spicifera were evaluated. Total phenolic content and reducing power of crude methanol extract were determined. The antioxidant activities of total methanol extract and five different solvent fractions (viz., petroleum ether (PE), ethyl acetate (EA), dichloromethane (DCM), butanol (BuOH) and aqueous) were also evaluated. EA fraction of A. spicifera exhibited higher total antioxidant activity (32.01 mg ascorbic acid equivalent/g extract) among all the fractions. Higher phenolic content (16.26 mg gallic acid equivalent/g extract) was noticed in PE fraction of G. edulis. Reducing power of crude methanol extract increased with increasing concentration of the extract. Reducing power and hydroxyl radical scavenging activity of E. kappaphycus were higher compared to standard antioxidant (alpha-tocopherol). The total phenol content of all the seaweeds was significantly different (P<0.05). In vitro antioxidant activities of methanol extracts of all the three seaweeds exhibited dose dependency; and increased with increasing concentration of the extract.

Phytochemical Characteristics, Free Radical Scavenging Activities, and Neuroprotection of Five Medicinal Plant Extracts

PubMed Central

Chang, Chia Lin; Lin, Che San; Lai, Guia Hung

2012-01-01

The objective of this study was to determine phytochemical characteristics, chemiluminescence antioxidant capacities, and neuroprotective effects on PC12 cells for methanol extracts of Spatholobus suberectus, Uncaria rhynchophylla, Alpinia officinarum, Drynaria fortunei, and Crataegus pinnatifida. The C. pinnatifida extract (CPE) afforded the greatest yield and total phenolic content. The S. suberectus extract (SSE) yielded the greatest total flavonoid content. The U. rhynchophylla extract (URE) produced the greatest total tannin content, and the A. officinarum extract (AOE) produced the greatest total triterpenoid content. The D. fortunei extract, assayed using horseradish peroxidase-luminol-hydrogen peroxide (H2O2), and AOE using pyrogallol-luminol assay each exhibited better antioxidant activity than the L-ascorbic acid and 6-hydroxy-2,5,7,8-tetramethylchroman-2-carboxylic acid did. The CPE, SSE, and URE presented neurogrowth effects and neuroprotective activities on H2O2-induced PC12 cell death at 0.5–5.0 μg/mL. The CPE represents a promising medicinal plant source for the treatment of H2O2-induced neurodegenerative disease, because of its useful phytochemical characteristics. PMID:21845204

Evaluation of radioprotective activities Rhodiola imbricata Edgew--a high altitude plant.

PubMed

Arora, Rajesh; Chawla, Raman; Sagar, Ravinder; Prasad, Jagdish; Singh, Surendar; Kumar, Raj; Sharma, Ashok; Singh, Shikha; Sharma, Rakesh Kumar

2005-05-01

The present study reports the radioprotective properties of a hydro-alcoholic rhizome extract of Rhodiola imbricata (code named REC-7004), a plant native to the high-altitude Himalayas. The radioprotective effect, along with its relevant superoxide ion scavenging, metal chelation, antioxidant, anti-lipid peroxidation and anti-hemolytic activities was evaluated under both in vitro and in vivo conditions. Chemical analysis showed the presence of high content of polyphenolics (0.971 +/- 0.01 mg% of quercetin). Absorption spectra analysis revealed constituents that absorb in the range of 220-290 nm, while high-performance liquid chromatography (HPLC) analysis confirmed the presence of four major peaks with retention times of 4.780, 5.767, 6.397 and 7.577 min. REC-7004 was found to lower lipid oxidation significantly (p < 0.05) at concentrations viz., 8 and 80 microg/ml respectively as compared to reduced glutathione, although the optimally protective dose was 80 microg/ml, which showed 59.5% inhibition of induction of linoleic acid degradation within first 24 h. The metal chelation activity of REC-7004 was found to increase concomitantly from 1 to 50 microg/ml. REC-7004 (10-50 microg/ml) exhibited significant metal chelation activity (p < 0.05), as compared to control, and maximum percentage inhibition (30%) of formation of iron-2,2'-bi-pyridyl complex was observed at 50 microg/ml, which correlated well with quercetin (34.9%), taken as standard. The reducing power of REC-7004 increased in a dose-dependent manner. The absorption unit value of REC-7004 was significantly lower (0.0183 +/- 0.0033) as compared to butylated hydroxy toluene, a standard antioxidant (0.230 +/- 0.091), confirming its high reducing ability. Superoxide ion scavenging ability of REC-7004 exhibited a dose-dependent increase (1-100 microg/ml) and was significantly higher (p < 0.05) than that of quercetin at lower concentrations (1-10 microg/ml), while at 100 microg/ml, both quercetin and REC-7004 scavenged over 90% superoxide anions. MTT assay in U87 cell line revealed an increase in percent survival of cells at doses between 25 and 125 microg/ml in case of drug + radiation group. In vivo evaluation of radio-protective efficacy in mice revealed that intraperitoneal administration of REC-7004 (maximally effective dose: 400 mg/kg b.w.) 30 min prior to lethal (10 Gy) total-body gamma-irradiation rendered 83.3% survival. The ability of REC-7004 to inhibit lipid peroxidation induced by iron/ascorbate, radiation (250 Gy) and their combination [i.e., iron/ascorbate and radiation (250 Gy)], was also investigated and was found to decrease in a dose-dependent manner (0.05-2 mg/ml). The maximum percent inhibition of formation of MDA-TBA complex at 2 mg/ml in case of iron/ascorbate, radiation (250 Gy) and both i.e., iron/ascorbate with radiation (250 Gy) was 53.78, 63.07, and 51.76% respectively and were found to be comparable to that of quercetin. REC-7004 (1 microg/ml) also exhibited significant anti-hemolytic capacity by preventing radiation-induced membrane degeneration of human erythrocytes. In conclusion, Rhodiola renders in vitro and in vivo radioprotection via multifarious mechanisms that act in a synergistic manner.

Exogenous ascorbic acid improves defence responses of sunflower (Helianthus annuus) exposed to multiple stresses.

PubMed

Kaya, Armagan

2017-09-01

Ascorbic acid is an important antioxidant that plays role both on growth and development and also stress response of the plant. The purpose of this study was to determine the effect of ascorbate on physiological and biochemical changes of sunflower that was exposed to multiple stresses. Chlorophyll and carotenoid contents decreased and glutathione, ascorbate and malondialdehyde contents as well as antioxidant enzyme activities increased for sunflower plant that was exposed to 50 mM NaCl and pendimethalin at different concentrations. These changes were found to be more significant in groups simultaneously exposed to both stress factors. While malondialdehyde content decreased, chlorophyll, carotenoid, ascorbate, glutathione contents and antioxidant enzyme activities increased in plants treated exogenously with ascorbate, compared to the untreated samples. According to the findings of our study; compared to individual stress, the effect of stress is more pronounced in sunflower exposed to multiple stresses, and treatment with exogenous ascorbate reduces the negative effects of stress.

DNA Damage Protecting Activity and Antioxidant Potential of Launaea taraxacifolia Leaves Extract.

PubMed

Adinortey, Michael Buenor; Ansah, Charles; Weremfo, Alexander; Adinortey, Cynthia Ayefoumi; Adukpo, Genevieve Etornam; Ameyaw, Elvis Ofori; Nyarko, Alexander Kwadwo

2018-01-01

The leaf extract of Launaea taraxacifolia commonly known as African Lettuce is used locally to treat dyslipidemia and liver diseases, which are associated with oxidative stress. Methanol extract from L. taraxacifolia leaves was tested for its antioxidant activity and its ability to protect DNA from oxidative damage. In vitro antioxidant potential of the leaf extract was evaluated using 1,1-diphenyl-2-picrylhydrazyl (DPPH), nitric oxide (NO), and hydroxyl (OH) radical scavenging assays. Ferric reducing power, total antioxidant capacity (TAC), metal chelating, and anti-lipid peroxidation ability of the extract were also examined using gallic acid, ascorbic acid, citric acid, and ethylenediaminetetraacetic acid as standards. L. taraxacifolia leaves extract showed antioxidant activity with IC 50 values of 16.18 μg/ml (DPPH), 123.3 μg/ml (NO), 128.2 μg/ml (OH radical), 97.94 μg/ml (metal chelating), 80.28 μg/ml (TAC), and 23 μg/ml (anti-lipid peroxidation activity). L. taraxacifolia leaves extract exhibited a strong capability for DNA damage protection at 20 mg/ml concentration. These findings suggest that the methanolic leaf extract of L. taraxacifolia could be used as a natural antioxidant and also as a preventive therapy against diseases such as arteriosclerosis associated with DNA damage.

Evaluation of chemical constituents and antioxidant activity of coconut water (Cocus nucifera L.) and caffeic acid in cell culture.

PubMed

Santos, João L A; Bispo, Vanderson S; Filho, Adriano B C; Pinto, Isabella F D; Dantas, Lucas S; Vasconcelos, Daiane F; Abreu, Fabíula F; Melo, Danilo A; Matos, Isaac A; Freitas, Florêncio P; Gomes, Osmar F; Medeiros, Marisa H G; Matos, Humberto R

2013-01-01

Coconut water contains several uncharacterized substances and is widely used in the human consumption. In this paper we detected and quantified ascorbic acid and caffeic acid and total phenolics in several varieties of coconut using HPLS/MS/MS (25.8 ± 0.6 µg/mL and 1.078 ± 0.013 µg/mL and 99.7 µg/mL, respectively, in the green dwarf coconut water, or 10 mg and 539 µg and 39.8 mg for units of coconut consumed, 500 ± 50 mL). The antioxidant potential of four coconut varieties (green dwarf, yellow dwarf, red dwarf and yellow Malaysian) was compared with two industrialized coconut waters and the lyophilized water of the green dwarf variety. All varieties were effective in scavenging the DPPH radical (IC₅₀=73 µL) and oxide nitric (0.1 mL with an IP of 29.9%) as well as in inhibiting the in vitro production of thiobarbituric acid reactive substances (1 mL with an IP of 34.4%), highlighting the antioxidant properties of the green dwarf which it is the most common used. In cell culture, the green dwarf water was efficient in protecting against oxidative damages induced by hydrogen peroxide.

Simultaneous and sensitive determination of ascorbic acid, dopamine, uric acid, and tryptophan with silver nanoparticles-decorated reduced graphene oxide modified electrode.

PubMed

Kaur, Balwinder; Pandiyan, Thangarasu; Satpati, Biswarup; Srivastava, Rajendra

2013-11-01

In this paper, we report the synthesis of silver nanoparticle-decorated reduced graphene oxide composite (AgNPs/rGO) by heating the mixture of graphene oxide and silver nitrate aqueous solution in the presence of sodium hydroxide. This material was characterized by means of X-ray diffraction, UV-vis spectroscopy, and transmission electron microscopy. AgNPs/rGO based electrochemical sensor was fabricated for the simultaneous determination of ascorbic acid, dopamine, uric acid, and tryptophan. Electrochemical studies were carried out by using cyclic voltammetry, linear sweep voltammetry, and chronoamperometry. AgNPs/rGO modified electrode exhibited excellent electrocatalytic activity, stability, sensitivity, and selectivity with well-separated oxidation peaks toward ascorbic acid, dopamine, uric acid, and tryptophan in the simultaneous determination of their quaternary mixture. The analytical performance of this material as a chemical sensor was demonstrated for the determination of ascorbic acid and dopamine in commercial pharmaceutical samples such as vitamin C tablets and dopamine injections, respectively. The applicability of this sensor was also extended in the determination of uric acid in human urine samples. Copyright © 2013 Elsevier B.V. All rights reserved.

Effect of combination treatment of gamma irradiation and ascorbic acid on physicochemical and microbial quality of minimally processed eggplant (Solanum melongena L.)

NASA Astrophysics Data System (ADS)

Hussain, Peerzada R.; Omeera, A.; Suradkar, Prashant P.; Dar, Mohd A.

2014-10-01

Gamma irradiation alone and in combination with ascorbic acid was tested for preventing the surface browning and maintaining the quality attributes of minimally processed eggplant. Eggplant samples after preparation were subjected to treatment of gamma irradiation in the dose range of 0.25-1.0 kGy and to combination treatments of ascorbic acid dip at a concentration of 2.0% w/v and gamma irradiation (dose range 0.5-2.0 kGy) followed by storage at 3±1 °C, RH 80%. Studies revealed inverse correlation (r=-0.93) between the polyphenol oxidase (PPO) activity, browning index and the treatments of ascorbic acid and gamma irradiation. Combinatory treatment of 2.0% w/v ascorbic acid and 1.0 kGy gamma irradiation proved to be significantly (p≤0.05) effective in inhibiting the PPO activity, preventing the surface browning and maintaining the creamy white color and other quality attributes of minimally processed eggplant up to 6 days of refrigerated storage. Sensory evaluation revealed that control and 0.25 kGy irradiated samples were unacceptable only after 3 days of storage. Samples irradiated at 0.5 kGy and 0.75 kGy were unacceptable after 6 days of storage. Microbial analysis revealed that radiation processing of minimally processed eggplant at 1.0 kGy with and without ascorbic acid resulted in around 1 and 1.5 log reduction in yeast and mold count as well as bacterial count just after treatment and 6 days of storage therefore, enhances the microbial safety.

Copper Complex in Poly(vinyl chloride) as a Nitric Oxide-Generating Catalyst for the Control of Nitrifying Bacterial Biofilms.

PubMed

Wonoputri, Vita; Gunawan, Cindy; Liu, Sanly; Barraud, Nicolas; Yee, Lachlan H; Lim, May; Amal, Rose

2015-10-14

In this study, catalytic generation of nitric oxide by a copper(II) complex embedded within a poly(vinyl chloride) matrix in the presence of nitrite (source of nitric oxide) and ascorbic acid (reducing agent) was shown to effectively control the formation and dispersion of nitrifying bacteria biofilms. Amperometric measurements indicated increased and prolonged generation of nitric oxide with the addition of the copper complex when compared to that with nitrite and ascorbic acid alone. The effectiveness of the copper complex-nitrite-ascorbic acid system for biofilm control was quantified using protein analysis, which showed enhanced biofilm suppression when the copper complex was used in comparison to that with nitrite and ascorbic acid treatment alone. Confocal laser scanning microscopy (CLSM) and LIVE/DEAD staining revealed a reduction in cell surface coverage without a loss of viability with the copper complex and up to 5 mM of nitrite and ascorbic acid, suggesting that the nitric oxide generated from the system inhibits proliferation of the cells on surfaces. Induction of nitric oxide production by the copper complex system also triggered the dispersal of pre-established biofilms. However, the addition of a high concentration of nitrite and ascorbic acid to a pre-established biofilm induced bacterial membrane damage and strongly decreased the metabolic activity of planktonic and biofilm cells, as revealed by CLSM with LIVE/DEAD staining and intracellular adenosine triphosphate measurements, respectively. This study highlights the utility of the catalytic generation of nitric oxide for the long-term suppression and removal of nitrifying bacterial biofilms.

The effect of L-ascorbic acid and/or tocopherol supplementation on electrophysiological parameters of the colon of rats chronically exposed to lead

PubMed Central

Kosik-Bogacka, Danuta I.; Baranowska-Bosiacka, Irena; Marchlewicz, Mariola; Kolasa, Agnieszka; Jakubowska, Katarzyna; Olszewska, Maria; Łanocha, Natalia; Wiernicki, Ireneusz; Millo, Barbara; Wiszniewska, Barbara; Chlubek, Dariusz

2011-01-01

Summary Background The aim of this study was to assess the effect of diet supplementation with L-ascorbic acid (500 mg/L), tocopherol (3 mg/kg b.w.), and/or a water soluble analog of tocopherol (Trolox) (48 mg/L) on ion transport in the colon of rats subjected to a chronic exposure (9 months) to 0.1% lead acetate in drinking water. Material/Methods The electrophysiological parameters of the colon wall were measured with Ussing methods. Lead content in the whole blood was analyzed by graphite furnace atomic absorption spectrometry (GFAAS) using Zeeman correction. L-ascorbic acid and tocopherol in plasma was measured by high performance liquid chromatography. Immunohistochemical reaction was carried out for visualization of occludin, the intracellular tight junction protein. Results We showed a strong inhibitory effect of lead on the electrophysiological parameters, changes in intestinal permeability, disappearance of junctional occludin, decreased amount of mucus covering the colon surface, and the accumulation of PAS-positive substance in the apical region of the cytoplasm in the absorptive cells. Conclusions Supplementation with tocopherol or Trolox did not exert a beneficial influence on the studied parameters. L-ascorbic acid positively influenced the examined electrophysiological parameters, as it cancelled the inhibitory influence of lead on ion transport in the rat colon. L-ascorbic acid also protected against tight junction disruption of epithelial cells in the colon of the lead-treated rats. A similar effect was observed in the group of rats receiving lead and supplemented with L-ascorbic acid plus Trolox. PMID:21169903

Problems and solutions of polyethylene glycol co-injection method in multiresidue pesticide analysis by gas chromatography-mass spectrometry: evaluation of instability phenomenon in type II pyrethroids and its suppression by novel analyte protectants.

PubMed

Akutsu, Kazuhiko; Kitagawa, Yoko; Yoshimitsu, Masato; Takatori, Satoshi; Fukui, Naoki; Osakada, Masakazu; Uchida, Kotaro; Azuma, Emiko; Kajimura, Keiji

2018-05-01

Polyethylene glycol 300 is commonly used as a base material for "analyte protection" in multiresidue pesticide analysis via gas chromatography-mass spectrometry. However, the disadvantage of the co-injection method using polyethylene glycol 300 is that it causes peak instability in α-cyano pyrethroids (type II pyrethroids) such as fluvalinate. In this study, we confirmed the instability phenomenon in type II pyrethroids and developed novel analyte protectants for acetone/n-hexane mixture solution to suppress the phenomenon. Our findings revealed that among the examined additive compounds, three lipophilic ascorbic acid derivatives, 3-O-ethyl-L-ascorbic acid, 6-O-palmitoyl-L-ascorbic acid, and 6-O-stearoyl-L-ascorbic acid, could effectively stabilize the type II pyrethroids in the presence of polyethylene glycol 300. A mixture of the three ascorbic acid derivatives and polyethylene glycol 300 proved to be an effective analyte protectant for multiresidue pesticide analysis. Further, we designed and evaluated a new combination of analyte protectant compounds without using polyethylene glycol or the troublesome hydrophilic compounds. Consequently, we obtained a set of 10 medium- and long-chain saturated fatty acids as an effective analyte protectant suitable for acetone/n-hexane solution that did not cause peak instability in type II pyrethroids. These analyte protectants will be useful in multiresidue pesticide analysis by gas chromatography-mass spectrometry in terms of ruggedness and reliable quantitativeness. Graphical abstract Comparison of effectiveness of the addition of lipophilic derivatives of ascorbic acid in controlling the instability phenomenon of fluvalinate with polyethylene glycol 300.

Plasma Levels of Folates, Riboflavin, Vitamin B6, and Ascorbate in Severely Disturbed Children.

ERIC Educational Resources Information Center

Sankar, D. V. Siva

1979-01-01

The plasma levels of folic acid, ascorbic acid, pyridoxine, and riboflavin were studied in 125 severely emotionally disturbed children (ages 5-16 years) to determine whether they had overt vitamin deficiencies. (Author/DLS)

Assessment of the cryopreservation of equine spermatozoa in the presence of enzyme scavengers and antioxidants.

PubMed

Baumber, Julie; Ball, Barry A; Linfor, Jennifer J

2005-05-01

To evaluate the effect of the addition of enzyme scavengers and antioxidants to the cryopreservation extender on characteristics of equine spermatozoa after freezing and thawing. 2 ejaculates collected from each of 5 stallions. Equine spermatozoa were cryopreserved in freezing extender alone (control samples) or with the addition of catalase (200 U/mL), superoxide dismutase (200 U/mL), reduced glutathione (10 mM), ascorbic acid (10 mM), alpha-tocopherol (25, 50, 100, or 500 microM or 1 mM), or the vehicle for alpha-tocopherol (0.5% ethanol). After thawing, spermatozoal motility was assessed via computer-assisted analysis and DNA fragmentation was assessed via the comet assay. Spermatozoal mitochondrial membrane potential, acrosomal integrity, and viability were determined by use of various specific staining techniques and flow cytometry. The addition of enzyme scavengers or antioxidants to cryopreservation extender did not improve spermatozoal motility, DNA fragmentation, acrosomal integrity, viability, or mitochondrial membrane potential after thawing. Superoxide dismutase increased DNA fragmentation, likely because of the additional oxidative stress caused by the generation of hydrogen peroxide by this enzyme. Interestingly, the addition of the vehicle for alpha-tocopherol resulted in a significant decrease in live acrosome-intact spermatozoa. The addition of antioxidants to the cryopreservation extender did not improve the quality of equine spermatozoa after thawing, which suggests that the role of oxidative stress in cryopreservation-induced damage of equine spermatozoa requires further investigation. Our data suggest that solubilizing alpha-tocopherol in ethanol may affect spermatozoal viability; consequently, water-soluble analogues of alpha-tocopherol may be preferred for future investigations.

Coconut (Cocos nucifera) Ethanolic Leaf Extract Reduces Amyloid-β (1-42) Aggregation and Paralysis Prevalence in Transgenic Caenorhabditis elegans Independently of Free Radical Scavenging and Acetylcholinesterase Inhibition

PubMed Central

Manalo, Rafael Vincent; Silvestre, Maries Ann; Barbosa, Aza Lea Anne; Medina, Paul Mark

2017-01-01

Virgin coconut oil (VCO) has been the subject of several studies which have aimed to alleviate Alzheimer’s disease (AD) pathology, focusing on in vitro antioxidant and acetylcholinesterase (AChE) inhibitory activities. Here, we studied an underutilized and lesser-valued part of the coconut tree, specifically the leaves, using in vitro and in vivo approaches. Coconut leaf extract (CLE) was screened for antioxidant and AChE inhibitory properties in vitro and therapeutic effects in two strains of transgenic Caenorhabditis elegans expressing amyloid-β1–42 (Aβ1-42) in muscle cells. CLE demonstrated free radical scavenging activity with an EC50 that is 79-fold less compared to ascorbic acid, and an AChE inhibitory activity that is 131-fold less compared to Rivastigmine. Surprisingly, in spite of its low antioxidant activity and AChE inhibition, CLE reduced Aβ deposits by 30.31% in CL2006 in a dose-independent manner, and reduced the percentage of paralyzed nematodes at the lowest concentration of CLE (159.38 μg/mL), compared to dH2O/vehicle (control). Phytochemical analysis detected glycosides, anthocyanins, and hydrolyzable tannins in CLE, some of which are known to be anti-amyloidogenic. Taken together, these findings suggest that CLE metabolites alternatively decrease AB1–42 aggregation and paralysis prevalence independently of free radical scavenging and AChE inhibition, and this warrants further investigation on the bioactive compounds of CLE. PMID:28536360

The effect of ascorbic acid ingestion on the biochemical and physicochemical risk factors associated with calcium oxalate kidney stone formation.

PubMed

Auer, B L; Auer, D; Rodgers, A L

1998-03-01

The present study was undertaken to determine the effect of ingestion of large doses of vitamin C on urinary oxalate excretion and on a number of other biochemical and physicochemical risk factors associated with calcium oxalate urolithiasis. A further objective was to determine urinary ascorbate excretion and to relate it qualitatively to ingested levels of the vitamin and oxalate excretion. Ten healthy males participated in a protocol in which 4 g ascorbic acid was ingested for 5 days. Urines (24 h) were collected prior to, during and after the protocol. The urine collection procedure was designed to allow for the analysis of oxalate in the presence and absence of an EDTA preservative and for the analysis of ascorbic acid by manual titration using 2,6 dichlorophenolindophenol. Physicochemical risk factors such as the calcium oxalate relative supersaturation and Tiselius risk index were calculated from urine composition. The results showed that erroneously high analytical oxalate levels occur in the asence of preservative. In the preserved samples there was no significant increase in oxalate excretion at any stage of the protocol. Ascorbate excretion increased when vitamin C ingestion commenced but levelled out after 24 hours suggesting that saturation of the metabolic pool is reached within 24 hours after which ingested ascorbic acid is excreted unmetabolized in the urine. While transient statistically significant changes occurred in some of the biochemical risk factors, they were not regarded as being clinically significant. There were no changes in either the calcium oxalate relative supersaturation or Tiselius risk index. It is concluded that ingestion of large doses of ascorbic acid does not affect the principal risk factors associated with calcium oxalate kidney stone formation.

Effects of genotype, latitude, and weather conditions on the composition of sugars, sugar alcohols, fruit acids, and ascorbic acid in sea buckthorn (Hippophaë rhamnoides ssp. mongolica) berry juice.

PubMed

Zheng, Jie; Yang, Baoru; Trépanier, Martin; Kallio, Heikki

2012-03-28

Sea buckthorn berries (Hippophaë rhamnoides ssp. mongolica) of nine varieties were collected from three growth locations in five inconsecutive years (n = 152) to study the compositional differences of sugars, sugar alcohols, fruit acids, and ascorbic acid in berries of different genotypes. Fructose and glucose (major sugars) were highest in Chuiskaya and Vitaminaya among the varieties studied, respectively. Malic acid and quinic acid (major acids) were highest in Pertsik and Vitaminaya, respectively. Ascorbic acid was highest in Oranzhevaya and lowest in Vitaminaya. Berry samples of nine varieties collected from two growth locations in five years (n = 124) were combined to study the effects of latitude and weather conditions on the composition of H. rhamnoides ssp. mongolica. Sea buckthorn berries grown at lower latitude had higher levels of total sugar and sugar/acid ratio and a lower level of total acid and were supposed to have better sensory properties than those grown at higher latitude. Glucose, quinic acid, and ascorbic acid were hardly influenced by weather conditions. The other components showed various correlations with temperature, radiation, precipitation, and humidity variables. In addition, fructose, sucrose, and myo-inositol correlated positively with each other and showed negative correlation with malic acid on the basis of all the samples studied (n = 152).

Radical scavenging activity of lipophilized products from lipase-catalyzed transesterification of triolein with cinnamic and ferulic acids.

PubMed

Choo, Wee-Sim; Birch, Edward John

2009-02-01

Lipase-catalyzed transesterification of triolein with cinnamic and ferulic acids using an immobilized lipase from Candida antarctica (E.C. 3.1.1.3) was conducted to evaluate the antioxidant activity of the lipophilized products as model systems for enhanced protection of unsaturated oil. The lipophilized products were identified using ESI-MS. Free radical scavenging activity was determined using the DPPH radical method. The polarity of the solvents proved important in determining the radical scavenging activity of the substrates. Ferulic acid showed much higher radical scavenging activity than cinnamic acid, which has limited activity. The esterification of cinnamic acid and ferulic acid with triolein resulted in significant increase and decrease in the radical scavenging activity, respectively. These opposite effects were due to the effect of addition of electron-donating alkyl groups on the predominant mechanism of reaction (hydrogen atom transfer or electron transfer) of a species with DPPH. The effect of esterification of cinnamic acid was confirmed using ethyl cinnamate which greatly enhances the radical scavenging activity. Although, compared to the lipophilized cinnamic acid product, the activity was lower. The radical scavenging activity of the main component isolated from lipophilized cinnamic acid product using solid phase extraction, monocinnamoyl dioleoyl glycerol, was as good as the unseparated mixture of lipophilized product. Based on the ratio of a substrate to DPPH concentration, lipophilized ferulic acid was a much more efficient radical scavenger than lipophilized cinnamic acid.

Vitamin C Content of Commercial Orange Juices

ERIC Educational Resources Information Center

Haddad, Paul

1977-01-01

Describes an experiment designed to confirm that newly purchased commercial orange juice contains sufficient ascorbic acid to meet government standards, and to establish the rate of aerial oxidation of this ascorbic acid when the juice is stored in a refrigerator. (MLH)

Properties of L-ascorbic acid in water and binary aqueous mixtures of D-glucose and D-fructose at different temperatures

NASA Astrophysics Data System (ADS)

Sharma, Ravi; Thakur, R. C.; Sani, Balwinder; Kumar, Harsh

2017-12-01

Using density and sound velocity partial molar volumes, partial molar adiabatic compressibilities, partial molar expansibilities and structure of L-ascorbic acid have been determined in water and aqueous mixtures of D-glucose and D-fructose at different concentrations and temperatures. Masson's equation was used to analyze the measured data. The obtained parameters have been interpreted in terms of solute-solute and solute-solvent interactions. It is found that the L-ascorbic acid acts as structure breaker in water as well in binary studied mixtures.

Vitamin C with metabolites reduce oxalate levels compared to ascorbic acid: a preliminary and novel clinical urologic finding.

PubMed

Moyad, Mark A; Combs, Maile A; Crowley, David C; Baisley, Joshua E; Sharma, Prachi; Vrablic, Angelica S; Evans, Malkanthi

2009-01-01

The incidence and prevalence of kidney stones are notable and are projected to increase over the next decade. Risk factors for kidney stones abound, but a prominent risk factor is hyperoxaluria, which has numerous etiologies, including vitamin C (ascorbic acid) dietary supplement intake. This randomized, double-blind, crossover study examined the effects of two different vitamin C formulations and found that vitamin C with metabolites (Ester-C) significantly reduced urine oxalate levels compared to ascorbic acid. This is a potential novel finding that requires further clinical evaluation.

[Enteral absoprtion of ascorbic acid in man after application of a micro-encapsulated retard preparation (author's transl)].

PubMed

Brenner, G

1975-07-11

Blood level determinations of ascorbic acid were carried out in 11 male probands after oral application of a new vitamin C retard preparation. In comparative tests the same probands received identical doses of a non retarded vitamine C preparations after a period without application of 2 weeks. The results obtained show that after application of the new vitamin C retard preparation the absorption of ascorbic acid is increased and thus a marked improvement of the bioavailability of vitamin C is attained as compared to the non retarded form.

[Cholesterol metabolism and lipid peroxidation processes in hypodynamia. Effect of using ascorbic acid and alpha-tocopherol].

PubMed

Elikov, A V; Tsapok, P I

2010-01-01

Study status of cholesterol metabolism, processes of lipid peroxidation and antioxidant protection in blood plasma, erythrocytes and homogenates of the, heart, liver, muscle femors of rats attached to movement active. Establishment effects application of ascorbic acid and alpha-tocopherol. Ascorbic acid and alpha-tocopherol were infused daily. The daily dosage was 2 and 1 mg respectively. Characteristic shift changes of cholesterol metabolism in conditions of limited muscular activity were revealed. It was shown that vitamin antioxidants play a role in correction of metabolic disorders in case of immobile distress syndrome.

[The effects of the combined use of mineral water with ascorbic acid and rutin experimentally and clinically].

PubMed

Polushina, N D; Kartazaeva, V A; Botvineva, L A; Kozhevnikov, S A

2000-01-01

Effects of a single and course intake of glucose, ascorbic acid and rutin in combination with mineral water Essentuki N17 on blood levels of glucose, hydrocortisone, ACTH, insulin were studied in 336 Wistar male rats. 80 patients with diabetes mellitus type I and II received a course of ascorutin and mineral water. Mineral water proved able to reduce a hyperglycemic effect of vitamins. A course of mineral water and ascorutin promotes improvement of carbohydrate, lipid metabolism, elevates plasma content of ascorbic acid, diminishes the need in sugar-reducing drugs.

Supplementation of ascorbic acid and alpha-tocopherol is useful to preventing bone loss linked to oxidative stress in elderly.

PubMed

Ruiz-Ramos, M; Vargas, L Alberto; Fortoul Van der Goes, T I; Cervantes-Sandoval, A; Mendoza-Nunez, V M

2010-06-01

To determine the effect of ascorbic acid and alpha-tocopherol on oxidative stress and bone mineral density (BMD) in elderly people. A double-blind, controlled clinical assay was carried out in a sample of 90 elderly subjects divided into three age-paired random groups with 30 subjects in each group. Group Tx0 received placebo, group Tx1 received 500 mg of ascorbic acid and 400 IU of alpha-tocopherol, whereas group Tx2 received 1,000 mg of ascorbic acid and 400 IU of alpha-tocopherol, for a 12-month period. We measured thiobarbituric acid reactive substances (TBARS), total antioxidant status (TAS), superoxide dismutase (SOD), and glutation peroxidase (GPx); BMD was obtained on DXA of hip and spine before and after the 12-month treatment period with supplementation of vitamins C and E. We found a positive correlation between hip-BMD and SOD (r = 0.298, p < 0.05) and GPx (r = 0.214, p < 0.05). Also, a significantly lower decrease of LPO (p < 0.05) was observed as linked with hip bone loss in the Tx2 group than in the Tx0 group. Our findings suggest that that administration of 1,000 mg of ascorbic acid together with 400 IU of alpha-tocopherol could be useful in preventing or aiding in the treatment of age-related osteoporosis.

Minocycline, but not ascorbic acid, increases motor activity and extends the life span of Drosophila melanogaster.

PubMed

Mora, Marylhi; Medina-Leendertz, Shirley J; Bonilla, Ernesto; Terán, Raikelin E; Paz, Milagros C; Arcaya, José Luis

2013-06-01

In the present study we compared the effects of minocycline and ascorbic acid in the life span, motor activity and lipid peroxidation of Drosophila melanogaster, in an effort to find a substance capable of providing protection against oxidative stress in aging. In the flies treated with minocycline a very significant increase in the life span (101 +/- 1.33 days) was observed when compared to those treated with ascorbic acid and controls (42.3% and 38.4%, respectively). The motor activity of minocycline treated flies also increased significantly with respect to control and ascorbic acid fed flies, from the 3rd to the 9th week of treatment. With regard to lipid peroxidation, it was found that the levels of malondialdehyde (MDA) in flies treated with minocycline showed no statistical differences to the control on the first day of treatment, but a significantly lower content on the day of 50% survival. In contrast, in flies treated with ascorbic acid significantly elevated levels of MDA compared to control and minocycline treated flies were detected throughout. These results suggest a protective effect of minocycline against oxidative stress and aging in D. melanogaster. An inhibitory effect on reactive oxygen species production may be an important contributing factor.

Morphological assessment of bone mineralization in tibial metaphyses of ascorbic acid-deficient ODS rats.

PubMed

Hasegawa, Tomoka; Li, Minqi; Hara, Kuniko; Sasaki, Muneteru; Tabata, Chihiro; de Freitas, Paulo Henrique Luiz; Hongo, Hiromi; Suzuki, Reiko; Kobayashi, Masatoshi; Inoue, Kiichiro; Yamamoto, Tsuneyuki; Oohata, Noboru; Oda, Kimimitsu; Akiyama, Yasuhiro; Amizuka, Norio

2011-08-01

Osteogenic disorder shionogi (ODS) rats carry a hereditary defect in ascorbic acid synthesis, mimicking human scurvy when fed with an ascorbic acid-deficient (aa-def) diet. As aa-def ODS rats were shown to feature disordered bone formation, we have examined the bone mineralization in this rat model. A fibrous tissue layer surrounding the trabeculae of tibial metaphyses was found in aa-def ODS rats, and this layer showed intense alkaline phosphatase activity and proliferating cell nuclear antigen-immunopositivity. Many osteoblasts detached from the bone surfaces and were characterized by round-shaped rough endoplasmic reticulum (rER), suggesting accumulation of malformed collagen inside the rER. Accordingly, fine, fragile fibrillar collagenous structures without evident striation were found in aa-def bones, which may result from misassembling of the triple helices of collagenous α-chains. Despite a marked reduction in bone formation, ascorbic acid deprivation seemed to have no effect on mineralization: while reduced in number, normal matrix vesicles and mineralized nodules could be seen in aa-def bones. Fine needle-like mineral crystals extended from these mineralized nodules, and were apparently bound to collagenous fibrillar structures. In summary, collagen mineralization seems unaffected by ascorbic acid deficiency in spite of the fine, fragile collagenous fibrils identified in the bones of our animal model.

Abscisic acid activates a Ca2+-calmodulin-stimulated protein kinase involved in antioxidant defense in maize leaves.

PubMed

Xu, Shucheng

2010-09-01

The role of a calcium-dependent and calmodulin (CaM)-stimulated protein kinase in abscisic acid (ABA)-induced antioxidant defense was determined in leaves of maize (Zea mays). In-gel kinase assays showed that treatments with ABA or H(2)O(2) induced the activation of a 49-kDa protein kinase and a 52-kDa protein kinase significantly. Furthermore, we showed that the 52-kDa protein kinase has the characteristics of CaM-stimulating activity and is sensitive to calcium-CaM-dependent protein kinase II (CaMK II) inhibitor KN-93 or CaM antagonist W-7. Treatments with ABA or H(2)O(2) not only induced the activation of the 52-kDa protein kinase, but also enhanced the total activities of the antioxidant enzymes, including catalase, ascorbate peroxidase, glutathione reductase, and superoxide dismutase. Such enhancements were blocked by pretreatment with a CaMK inhibitor and a reactive oxygen species (ROS) inhibitor or scavenger. Pretreatment with the CaMK inhibitor also substantially arrested the ABA-induced H(2)O(2) production. Kinase activity enhancements induced by ABA were attenuated by pretreatment with an ROS inhibitor or scavenger. These results suggest that the 52-kDa CaMK is involved in ABA-induced antioxidant defense and that cross-talk between CaMK and H(2)O(2) plays a pivotal role in ABA signaling. We infer that CaMK acts both upstream and downstream of H(2)O(2), but mainly acts between ABA and H(2)O(2) in ABA-induced antioxidant-defensive signaling.

Effect of photo-selective nettings on post-harvest quality and bioactive compounds in selected tomato cultivars.

PubMed

Selahle, Maphoko Kamogelo; Sivakumar, Dharini; Soundy, Puffy

2014-08-01

Photo-selective coloured netting is referred to as a 'new agro-technological' concept adopted to manipulate light quality changes that can induce favourable responses in plants. Tomato (Solanum lycopersicum L.) cultivars AlvaV, Irit and SCX 248 grown under the black net (commercial net, 25% shading) showed higher weight loss, loss of firmness, ascorbic acid content and decline in the ratio of soluble solids content/titrable acidity during post-harvest storage (low-temperature storage at 10°C and 90% relative humidity for 21 days followed by market shelf conditions at 25°C for 2 days). During post-harvest storage, lycopene, β-carotene, total phenolic content and antioxidant scavenging activity were higher in cvs AlfaV and Irit grown under the black or pearl nets. However, the β-carotene, total phenolic content and antioxidant scavenging activity were higher in SCX 248 grown under the red net during post-harvest storage. Cultivar AlfaV grown under the red and pearl nets had a higher number of odour active aroma compounds during post-harvest storage. Panellists preferred cv. AlfaV grown under the pearl nets after storage based on taste, overall appearance and firm textured fruits. Pearl photo-selective nets retained the overall fruit quality and bioactive components in cvs AlfaV and Irit during post-harvest storage. Red photo-selective nets, however, showed greater influence on retention of overall fruit quality and bioactive compounds in cv. SCX 248 during post-harvest storage. © 2013 Society of Chemical Industry.

Abiotic Stress Tolerance in Plants: Myriad Roles of Ascorbate Peroxidase

PubMed Central

Pandey, Saurabh; Fartyal, Dhirendra; Agarwal, Aakrati; Shukla, Tushita; James, Donald; Kaul, Tanushri; Negi, Yogesh K.; Arora, Sandeep; Reddy, Malireddy K.

2017-01-01

One of the most significant manifestations of environmental stress in plants is the increased production of Reactive Oxygen Species (ROS). These ROS, if allowed to accumulate unchecked, can lead to cellular toxicity. A battery of antioxidant molecules is present in plants for keeping ROS levels under check and to maintain the cellular homeostasis under stress. Ascorbate peroxidase (APX) is a key antioxidant enzyme of such scavenging systems. It catalyses the conversion of H2O2 into H2O, employing ascorbate as an electron donor. The expression of APX is differentially regulated in response to environmental stresses and during normal plant growth and development as well. Different isoforms of APX show differential response to environmental stresses, depending upon their sub-cellular localization, and the presence of specific regulatory elements in the upstream regions of the respective genes. The present review delineates role of APX isoforms with respect to different types of abiotic stresses and its importance as a key antioxidant enzyme in maintaining cellular homeostasis. PMID:28473838

The Ascorbate-glutathione-α-tocopherol Triad in Abiotic Stress Response

PubMed Central

Szarka, András; Tomasskovics, Bálint; Bánhegyi, Gábor

2012-01-01

The life of any living organism can be defined as a hurdle due to different kind of stresses. As with all living organisms, plants are exposed to various abiotic stresses, such as drought, salinity, extreme temperatures and chemical toxicity. These primary stresses are often interconnected, and lead to the overproduction of reactive oxygen species (ROS) in plants, which are highly reactive and toxic and cause damage to proteins, lipids, carbohydrates and DNA, which ultimately results in oxidative stress. Stress-induced ROS accumulation is counteracted by enzymatic antioxidant systems and non-enzymatic low molecular weight metabolites, such as ascorbate, glutathione and α-tocopherol. The above mentioned low molecular weight antioxidants are also capable of chelating metal ions, reducing thus their catalytic activity to form ROS and also scavenge them. Hence, in plant cells, this triad of low molecular weight antioxidants (ascorbate, glutathione and α-tocopherol) form an important part of abiotic stress response. In this work we are presenting a review of abiotic stress responses connected to these antioxidants. PMID:22605990

Evaluation of synergistic antioxidant potential of complex mixtures using oxygen radical absorbance capacity (ORAC) and electron paramagnetic resonance (EPR).

PubMed

Parker, Tory L; Miller, Samantha A; Myers, Lauren E; Miguez, Fernando E; Engeseth, Nicki J

2010-01-13

Previous research has demonstrated that certain combinations of compounds result in a decrease in toxic or pro-oxidative effects, previously noted when compounds were administered singly. Thus, there is a need to study many complex interactions further. Two in vitro techniques [electron paramagnetic resonance (EPR) and oxygen radical absorbance capacity (ORAC) assays] were used in this study to assess pro- and antioxidant capacity and synergistic potential of various compounds. Rutin, p-coumaric acid, abscisic acid, ascorbic acid, and a sugar solution were evaluated individually at various concentrations and in all 26 possible combinations at concentrations found in certain foods (honey or papaya), both before and after simulated digestion. EPR results indicated sugar-containing combinations provided significantly higher antioxidant capacity; those combinations containing sugars and ascorbic acid demonstrated synergistic potential. The ORAC assay suggested additive effects, with some combinations having synergistic potential, although fewer combinations were significantly synergistic after digestion. Finally, ascorbic acid, caffeic acid, quercetin, and urate were evaluated at serum-achievable levels. EPR analysis did not demonstrate additive or synergistic potential, although ORAC analysis did, principally in combinations containing ascorbic acid.

A study on the activities of a few free radicals scavenging enzymes present in five roadside plants.

PubMed

Mandal, M; Mukherji, S

2001-10-01

The road side plants are continuously exposed to the high levels of oxides of nitrogen and sulphur dioxide, emitted from automobile. Resistance to automobile exhaust pollution was studied with Nerium indicum Mill, Boerhaavia diffusa L., Amaranthus spinosus L., Cephalandra indica Naud., and Tabernaemontana divaricata L., growing on the edges of Delhi Road, National Highway 2 (NH 2) near Dankuni, West Bengal. By analysing the activities of a few enzymes like superoxide dismutase, catalase, ascorbate peroxidase, glutathione reductase and phenolic peroxidase, it appears that among the five plants examined,Amaranthus and Cephalandra are equipped with a very good scavenging system to combat effects of air pollution.

Total polyphenolic contents and in vitro antioxidant properties of eight Sida species from Western Ghats, India

PubMed Central

Subramanya, M. D.; Pai, Sandeep R.; Upadhya, Vinayak; Ankad, Gireesh M.; Bhagwat, Shalini S.; Hegde, Harsha V.

2015-01-01

Background: Sida L., is a medicinally important genus, the species of which are widely used in traditional systems of medicine in India. Pharmacologically, roots are known for anti-tumor, anti-HIV, hepatoprotective, and many other properties. Phenolic antioxidants help in reducing oxidative stress occurring during treatment of such diseases. Objective: The study aimed to evaluate and compare polyphenol contents and antioxidant properties of eight selected species of Sida from Western Ghats, India. Materials and Methods: Methanolic root extracts (10% w/v) of Sida species, viz., S. acuta, S. cordata, S. cordifolia, S. indica, S. mysorensis, S. retusa, S. rhombifolia, and S. spinosa were analyzed. Results: Sida cordifolia possessed highest total phenolic content (TPC: 1.92 ± 0.10 mg Caffeic Acid Equivalent/g and 2.13 ± 0.11 mg Tannic Acid Equivalant/g), total flavonoid content (TF: 2.60 ± 0.13 mg Quercetin Equivalent/g) and also possessed highest antioxidant activities in 2,2-diphenylpicrylhydrazyl (DPPH) radical scavenging (51.31 ± 2.57% Radical Scavenging Activity, (RSA); Trolox Equivalent Antioxidant Capacity: 566.25 ± 28.31μM; Ascorbic acid Equivalent Antioxidant Capacity: 477.80 ± 23.89 μM) and Ferric Reducing Antioxidant Power assays (TEAC: 590.67 ± 29.53 μM; AEAC: 600.67 ± 30.03 μM). Unlike DPPH and Ferric Reducing Antioxidant Power (FRAP) activity, 2, 2′-Azinobis (3-ethyl Benzo Thiazoline-6-Sulfonic acid) ABTS+ antioxidant activity was highest in S. indica (TEAC: 878.44 ± 43.92 μM; AEAC 968.44 ± 48.42 μM). It was significant to note that values of AEAC (μM) for all the antioxidant activities analyzed were higher than that of TEAC. Conclusion: The high contents of phenolic compounds in the root extracts of selected Sida species have direct correlation with their antioxidant properties. Conclusively, roots of S. cordifolia can be considered as the potential source of polyphenols and antioxidants. PMID:25878460

Total polyphenolic contents and in vitro antioxidant properties of eight Sida species from Western Ghats, India.

PubMed

Subramanya, M D; Pai, Sandeep R; Upadhya, Vinayak; Ankad, Gireesh M; Bhagwat, Shalini S; Hegde, Harsha V

2015-01-01

Sida L., is a medicinally important genus, the species of which are widely used in traditional systems of medicine in India. Pharmacologically, roots are known for anti-tumor, anti-HIV, hepatoprotective, and many other properties. Phenolic antioxidants help in reducing oxidative stress occurring during treatment of such diseases. The study aimed to evaluate and compare polyphenol contents and antioxidant properties of eight selected species of Sida from Western Ghats, India. Methanolic root extracts (10% w/v) of Sida species, viz., S. acuta, S. cordata, S. cordifolia, S. indica, S. mysorensis, S. retusa, S. rhombifolia, and S. spinosa were analyzed. Sida cordifolia possessed highest total phenolic content (TPC: 1.92 ± 0.10 mg Caffeic Acid Equivalent/g and 2.13 ± 0.11 mg Tannic Acid Equivalant/g), total flavonoid content (TF: 2.60 ± 0.13 mg Quercetin Equivalent/g) and also possessed highest antioxidant activities in 2,2-diphenylpicrylhydrazyl (DPPH) radical scavenging (51.31 ± 2.57% Radical Scavenging Activity, (RSA); Trolox Equivalent Antioxidant Capacity: 566.25 ± 28.31μM; Ascorbic acid Equivalent Antioxidant Capacity: 477.80 ± 23.89 μM) and Ferric Reducing Antioxidant Power assays (TEAC: 590.67 ± 29.53 μM; AEAC: 600.67 ± 30.03 μM). Unlike DPPH and Ferric Reducing Antioxidant Power (FRAP) activity, 2, 2'-Azinobis (3-ethyl Benzo Thiazoline-6-Sulfonic acid) ABTS(+) antioxidant activity was highest in S. indica (TEAC: 878.44 ± 43.92 μM; AEAC 968.44 ± 48.42 μM). It was significant to note that values of AEAC (μM) for all the antioxidant activities analyzed were higher than that of TEAC. The high contents of phenolic compounds in the root extracts of selected Sida species have direct correlation with their antioxidant properties. Conclusively, roots of S. cordifolia can be considered as the potential source of polyphenols and antioxidants.

Pharmacological evaluation of Musa seminifera Lour. fruit.

PubMed

Saha, Sanjib; Hossain, Faroque; Anisuzzman, Md; Islam, Md Khirul

2013-07-01

To study potential antioxidant, analgesic, antidiarrheal, and antibacterial activities of the ethanol extract of Musa seminifera Lour. fruit in different established in vivo and in vitro experimental models. In vitro antioxidant activity was studied in 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical-scavenging assay. Phenolic content was determined using Folin-Ciocalteu's reagent. Reducing ability was evaluated by ferric reducing power assay. Peripherally and centrally acting analgesic activity was studied in three different in vivo models, namely, acetic acid-induced writhing, hot-plate test, and tail-flick test in Swiss albino mice. In vivo antidiarrheal activity was evaluated in castor oil- and magnesium sulfate-induced diarrhea in mice. Gastrointestinal motility test was also carried out in mice. All studies in mice were undertaken at the doses of 250 and 500 mg/kg body weight. Antibacterial activity was assessed by disk diffusion assay against some Gram-positive and Gram-negative bacterial strains. Acute toxicity test was conducted to assess the safe doses of the extract. The extract showed 50% inhibitory concentration value of 12.65 μg/mL in DPPH radical-scavenging assay. Phenolic content was found to be 589.83 mg gallic acid equivalent per 100 g of dried fruits extract. Reducing power was in a concentration-dependent manner, and strongly comparable with the standard ascorbic acid. The extract demonstrated significant inhibition of writhing in acetic acid-induced writhing test at both dose levels (P<0.01). The extract also raised pain threshold in both hot-plate and tail-flick test in a dose-dependent manner, and the results were statistically significant (P<0.01). The extract significantly (P<0.01) increased latent period, and decreased defecation in both castor oil- and magnesium sulfate-induced diarrhea. The extract also decreased gastrointestinal motility in mice. In disk diffusion assay, the extract showed potential antibacterial activity against all the tested bacterial strains. The results suggest that the ethanol extract of M. seminifera fruit has potential antioxidant, analgesic, antidiarrheal, and antibacterial activities.

Phytochemical Constituents, ChEs and Urease Inhibitions, Antiproliferative and Antioxidant Properties of Elaeagnus umbellata Thunb.

PubMed

Ozen, Tevfik; Yenigun, Semiha; Altun, Muhammed; Demirtas, Ibrahim

2017-01-01

Due to the common ethnopharmacological used or scientifically examined biochemical properties, Elaeagnaceae family, Elaeagnus umbellate (Thunb.) (EU, Guz yemisi) was worth investigating. In this investigation, we revealed antioxidant, antiproliferative and enzyme inhibition activities of the water, methanol, ethanol, acetone, ethyl acetate and hexane extracts of EU as well as the contents of their phenolic, flavonoid, anthocyanin, ascorbic acid, lycopene and β- carotene. The antioxidant activity was screened by total antioxidant (phosphomolybdenum), inhibition of linoleic acid peroxidation, reducing power, 2-deoxyribose degradation assay, H2O2 scavenging and metal chelating activities of the samples were tested in vitro. Additionally, the scavenging activities of the extracts were determined against 1,1-diphenyl-2-picrylhydrazyl (DPPH˙), 2,2-azino-bis(3-ethylbenzothiazloine-6-sulfonicacid (ABTS˙+), superoxide anion and peroxide radicals. The samples were determined for their inhibitory activities against urease, acetylcholinesterase (AChE) and butyrylcholinesterase (BuChE). In vitro, antiproliferative activities of six different extracts were tested using the xCELLigence system against HeLa and HT29 cell lines. The antioxidant activities of the extracts were found higher than standard antioxidants. The water extracts of fruit and leaf showed the best antioxidant activity. In inhibition assays of urease, AChE and BuChE, all extracts exhibited remarkable inhibition potential. Ethyl acetate extracts, especially, showed better inhibition capacity. It was found that the antioxidant activities of the extracts presented consistently with their chemical contents. The antiproliferative activities of leaf extracts were more effective than the fruit extracts. The chromatographic methods were applied to the different solvents to analyses phenolic secondery metabolites. It was found that fumaric acid, 4- hydroxybenzoic acid, rutin and quercetin-3-β-D-glucoside, neohesperidin, hesperidin determined to have higher contents all the extracts. EU can be suggested as a potential natural source of antioxidants appropriate for utilization in nutritional/pharmaceutical fields. Copyright© Bentham Science Publishers; For any queries, please email at epub@benthamscience.org.

Effects of salinity on the growth, physiology and relevant gene expression of an annual halophyte grown from heteromorphic seeds

PubMed Central

Cao, Jing; Lv, Xiu Yun; Chen, Ling; Xing, Jia Jia; Lan, Hai Yan

2015-01-01

Seed heteromorphism provides plants with alternative strategies for survival in unfavourable environments. However, the response of descendants from heteromorphic seeds to stress has not been well documented. Suaeda aralocaspica is a typical annual halophyte, which produces heteromorphic seeds with disparate forms and different germination characteristics. To gain an understanding of the salt tolerance of descendants and the impact of seed heteromorphism on progeny of this species, we performed a series of experiments to investigate the plant growth and physiological parameters (e.g. osmolytes, oxidative/antioxidative agents and enzymes), as well as expression patterns of corresponding genes. Results showed that osmolytes (proline and glycinebetaine) were significantly increased and that excess reactive oxygen species (O2−, H2O2) produced under high salinity were scavenged by increased levels of antioxidant enzymes (superoxide dismutase, ascorbate peroxidase and glutathione reductase) and corresponding antioxidants (ascorbic acid and glutathione). Moreover, enhancement of phosphoenolpyruvate carboxylase activity at high salt intensity had a positive effect on photosynthesis. The descendants from heteromorphic seeds presented no significant difference in performance with or without salinity. In conclusion, we found that high salinity induced the same active physiological responses in plants from heteromorphic seeds of S. aralocaspica, there was no carry-over of seed heteromorphism to plants: all the descendants required salinity for optimal growth and adaptation to their natural habitat. PMID:26386128

ASCORBIC ACID IS DECREASED IN INDUCED SPUTUM OF MILD ASTHMATICS

EPA Science Inventory

Asthma is primarily an airways inflammatory disease, and the bronchial airways have been shown to be particularly susceptible to oxidant-induced tissue damage. The antioxidant ascorbic acid (AA) plays an essential role in defending against oxidant attack in the airways. Decreased...

The effect of gold kiwifruit consumed with an iron fortified breakfast cereal meal on iron status in women with low iron stores: A 16 week randomised controlled intervention study

PubMed Central

2010-01-01

Background Dietary treatment is often recommended as the first line of treatment for women with mild iron deficiency. Although it is well established that ascorbic acid enhances iron absorption, it is less clear whether the consumption of ascorbic acid rich foods (such as kiwifruit) with meals fortified with iron improves iron status. The aim of this study is to investigate whether the consumption of ZESPRI® GOLD kiwifruit (a fruit high in ascorbic acid and carotenoids) with an iron fortified breakfast cereal meal increases iron status in women with low iron stores. Methods/Design Eighty nine healthy women aged 18-44 years with low iron stores (serum ferritin (SF) ≤ 25 μg/L, haemoglobin (Hb) ≥ 115 g/L) living in Auckland, New Zealand were randomised to receive an iron fortified breakfast cereal (16 mg iron per serve) and either two ZESPRI® GOLD kiwifruit or a banana (low ascorbic acid and carotenoid content) to eat at breakfast time every day for 16 weeks. Iron status (SF, Hb, C-reactive protein (CRP) and soluble transferrin receptor (sTfR)), ascorbic acid and carotenoid status were measured at baseline and after 16 weeks. Anthropometric measures, dietary intake, physical activity and blood loss were measured before and after the 16 week intervention. Discussion This randomised controlled intervention study will be the first study to investigate the effect of a dietary based intervention of an iron fortified breakfast cereal meal combined with an ascorbic acid and carotenoid rich fruit on improving iron status in women with low iron stores. Trial registration ACTRN12608000360314 PMID:20102633

Protective effects of ascorbic acid and garlic extract against lead-induced apoptosis in developing rat hippocampus.

PubMed

Ebrahimzadeh-Bideskan, Ali-Reza; Hami, Javad; Alipour, Fatemeh; Haghir, Hossein; Fazel, Ali-Reza; Sadeghi, Akram

2016-10-01

Lead exposure has negative effects on developing nervous system and induces apoptosis in newly generated neurons. Natural antioxidants (i.e. Ascorbic acid and Garlic) might protect against lead-induced neuronal cell damage. The aim of the present study was to investigate the protective effects of Ascorbic acid and Garlic administration during pregnancy and lactation on lead-induced apoptosis in rat developing hippocampus. Timed pregnant Wistar rats were administrated with Lead (1500 ppm) via drinking water (Pb group) or lead plus Ascorbic acid (Pb + AA Group, 500 mg/kg, IP), or lead plus Garlic Extract (Pb + G Group, 1 ml garlic juice/100 g BW, via Gavage) from early gestation (GD 0) until postnatal day 50 (PN 50). At the end of experiments, the pups' brains were carefully dissected. To identify neuronal death, the brain sections were stained with TUNEL assay. Mean of blood and brain lead levels increased significantly in Pb group comparing to other studied groups (P < 0.01). There was significant reduction in blood and brain lead level in Pb + AA and Pb + G groups when compared to those of Pb group (P < 0.01). The mean number of TUNEL positive cells in the CA1, CA3, and DG was significantly lower in the groups treated by either Ascorbic acid or Garlic (P < 0.05). Administration of Ascorbic acid and Garlic during pregnancy and lactation protect against lead-induced neuronal cell apoptosis in the hippocampus of rat pups partially via the reduction of Pb concentration in the blood and in the brain.

The role of topically applied L-ascorbic acid in ex-vivo examination of burn-injured human skin

NASA Astrophysics Data System (ADS)

Pielesz, Anna; Biniaś, Dorota; Bobiński, Rafał; Sarna, Ewa; Paluch, Jadwiga; Waksmańska, Wioletta

2017-10-01

Wound treatment and healing is complex and is comprised of an elaborate set of processes including cellular, spectroscopic and biochemical ones as well as the ;reaction; of local tissue to thermal injury. Vitamin C as L-ascorbic acid (LA) prevents injurious effects of oxidants because it reduces reactive oxygen species to stable molecules, it becomes oxidized to the short-lived ascorbyl radical. As a result, antioxidant treatment may contribute to minimizing injury in burn patients. The aim of this study is to assess changes in molecular structure of collagen extracted from human epidermis burn wound scab during incubation of the epidermis in L-ascorbic acid solution. The study will be performed using FTIR and FT Raman spectroscopies. During this research it was observed that the intensity of Raman peaks increased where healing was being modified by LA. The intensity of the amide III band at 1247 cm- 1 relative to the intensity at 1326 cm- 1 was used to test tissue repair degree at the incision site. FTIR spectra were recorded from frozen specimens of serum modified by LA; an analysis of shifts in the amide I band position was conducted. The appearance of a new band for frozen samples modified by LA was observed around 1149-1220 cm- 1. The above conclusions confirmed the creation of hydrogen bonds between Nsbnd H stretch and Cdbnd O. Samples being incubated in solutions of L-ascorbic acid demonstrated the absence of electrophoretic bands of albumin. Alterations in the surface of the skin incubated in L-ascorbic acid were investigated with the use of Scanning Electron Microscopy (SEM). A decrease in external symptoms of burn injury was noted in the damaged epidermis incubated in L-ascorbic acid.

Toxicity of nickel and silver to Nostoc muscorum: interaction with ascorbic acid, glutathione, and sulfur-containing amino acids

DOE Office of Scientific and Technical Information (OSTI.GOV)

Rai, L.C.; Raizada, M.

1987-08-01

Exposure of Nostoc muscorum to different concentrations of Ni and Ag brought about reduction in growth, carbon fixation, heterocyst production, and nitrogenase activity and increase in the loss of ions (K+, Na+). In an attempt to ameliorate the toxicity of test metals by ascorbic acid, glutathione, and sulfur-containing amino acids (L-cysteine and L-methionine), it was found that the level of protection by ascorbic acid and glutathione was more for Ag than Ni. However, metal-induced inhibition of growth and carbon fixation was equally ameliorated by methionine. But the level of protection by cysteine was quite different, i.e., 27% for Ni andmore » 22% for Ag. Protection of metal toxicity in N. muscorum by amino acids lends further support to self-detoxifying ability of cyanobacteria because they are known to synthesize all essential amino acids.« less

Efficient depletion of ascorbate by amino acid and protein radicals under oxidative stress.

PubMed

Domazou, Anastasia S; Zelenay, Viviane; Koppenol, Willem H; Gebicki, Janusz M

2012-10-15

Ascorbate levels decrease in organisms subjected to oxidative stress, but the responsible reactions have not been identified. Our earlier studies have shown that protein C-centered radicals react rapidly with ascorbate. In aerobes, these radicals can react with oxygen to form peroxyl radicals. To estimate the relative probabilities of the reactions of ascorbate with protein C- and O-centered radicals, we measured by pulse radiolysis the rate constants of the reactions of C-centered radicals in Gly, Ala, and Pro with O₂ and of the resultant peroxyl radicals with ascorbate. Calculations based on the concentrations of ascorbate and oxygen in human tissues show that the relative probabilities of reactions of the C-centered amino acid radicals with O₂ and ascorbate vary between 1:2.6 for the pituitary gland and 1:0.02 for plasma, with intermediate ratios for other tissues. The high frequency of occurrence of Gly, Ala, and Pro in proteins and the similar reaction rate constants of their C-centered radicals with O₂ and their peroxo-radicals with ascorbate suggest that our results are also valid for proteins. Thus, the formation of protein C- or O-centered radicals in vivo can account for the loss of ascorbate in organisms under oxidative stress. Copyright © 2012 Elsevier Inc. All rights reserved.

Vitamin C transport and its role in the central nervous system

PubMed Central

May, James M.

2013-01-01

Vitamin C, or ascorbic acid, is important as an antioxidant and participates in numerous cellular functions. Although it circulates in plasma in micromolar concentrations, it reaches millimolar concentrations in most tissues. These high ascorbate cellular concentrations are thought to be generated and maintained by the SVCT2 (Slc23a2), a specific transporter for ascorbate. The vitamin is also readily recycled from its oxidized forms inside cells. Neurons in the central nervous system (CNS) contain some of the highest ascorbic acid concentrations of mammalian tissues. Intracellular ascorbate serves several functions in the CNS, including antioxidant protection, peptide amidation, myelin formation, synaptic potentiation, and protection against glutamate toxicity. The importance of the SVCT2 for CNS function is supported by the finding that its targeted deletion in mice causes widespread cerebral hemorrhage and death on post-natal day one. Neuronal ascorbate content as maintained by this protein also has relevance for human disease, since ascorbate supplements decrease infarct size in ischemia-reperfusion injury models of stroke, and since ascorbate may protect neurons from the oxidant damage associated with neurodegenerative diseases such as Alzheimer’s, Parkinson’s, and Huntington’s. The aim of this review is to assess the role of the SVCT2 in regulating neuronal ascorbate homeostasis and the extent to which ascorbate affects brain function and antioxidant defenses in the CNS. PMID:22116696

Ascorbate protects endothelial barrier function during septic insult: Role of protein phosphatase type 2A.

PubMed

Han, Min; Pendem, Suresh; Teh, Suet Ling; Sukumaran, Dinesh K; Wu, Feng; Wilson, John X

2010-01-01

Endothelial barrier dysfunction contributes to morbidity in sepsis. We tested the hypothesis that raising the intracellular ascorbate concentration protects the endothelial barrier from septic insult by inhibiting protein phosphatase type 2A. Monolayer cultures of microvascular endothelial cells were incubated with ascorbate, dehydroascorbic acid (DHAA), the NADPH oxidase inhibitors apocynin and diphenyliodonium, or the PP2A inhibitor okadaic acid and then were exposed to septic insult (lipopolysaccharide and interferon-gamma). Under standard culture conditions that depleted intracellular ascorbate, septic insult stimulated oxidant production and PP2A activity, dephosphorylated phosphoserine and phosphothreonine residues in the tight junction-associated protein occludin, decreased the abundance of occludin at cell borders, and increased monolayer permeability to albumin. NADPH oxidase inhibitors prevented PP2A activation and monolayer leak, showing that these changes required reactive oxygen species. Okadaic acid, at a concentration that inhibited PP2A activity and monolayer leak, prevented occludin dephosphorylation and redistribution, implicating PP2A in the response of occludin to septic insult. Incubation with ascorbate or DHAA raised intracellular ascorbate concentrations and mitigated the effects of septic insult. In conclusion, ascorbate acts within microvascular endothelial cells to inhibit septic stimulation of oxidant production by NADPH oxidase and thereby prevents PP2A activation, PP2A-dependent dephosphorylation and redistribution of occludin, and disruption of the endothelial barrier. Copyright 2009 Elsevier Inc. All rights reserved.

[Effect of temperature on the aerobic degradation of vitamin C in citric fruit juices].

PubMed

Alvarado, J D; Palacios Viteri, N

1989-12-01

By means of the method of the 2,4-dinitrophenylhydrazine the total ascorbic acid content in lima, lemon, tangerine and grapefruit juices, fresh and kept at four temperatures and different times, was determined. It was confirmed that in all the cases, the aerobic degradation of ascorbic acid follows a kinetic first order and that the values of the reaction rate are different between species and even between varieties of lemon and tangerine. The values of the equation terms are reported, and examples of application given. Within a range from 20 degrees to 92 degrees C, the effect of temperature on the velocity of the ascorbic acid degradation is described satisfactorily following the Arrhenius equation, in accordance with which, the corresponding values of activation energy are calculated to compare them with other published values. With the simple application of the method, in two steps, and considering that the L-ascorbic acid and the L-dehydroascorbic acid are predominant, the results can be used to calculate the vitamin C losses in citric fruit juices, indicated when they are processed by traditional thermal treatments.

Electrospray ionization mass spectrometric investigations of [alpha]-dicarbonyl compounds--Probing intermediates formed in the course of the nonenzymatic browning reaction of l-ascorbic acid

NASA Astrophysics Data System (ADS)

Schulz, Anke; Trage, Claudia; Schwarz, Helmut; Kroh, Lothar W.

2007-05-01

A new method is presented which allows the simultaneous detection of various [alpha]-dicarbonyl compounds generated in the course of the nonenzymatic browning reaction initiated by thermal treatment of l-ascorbic acid, namely: glyoxal, methylglyoxal, diacetyl, 3-deoxy-l-pentosone, and l-threosoneE 3-Deoxy-l-threosone was successfully identified as a new C4-[alpha]-dicarbonyl structure for the first time in the degradation of Vitamin C by application of this non-chromatographic mass spectrometric approach. Moreover, a more detailed elucidation of the mechanistic scenario with respect to the oxidative and nonoxidative pathways is presented by using dehydro-l-ascorbic acid and 2,3-diketo-l-gulonic acid instead of l-ascorbic acid as a starting material. Furthermore, the postulated pathways are corroborated with the aid of 13C-isotopic labeling studies. The investigations were extended to baby food, and the successful detection of [alpha]-dicarbonyl compounds characteristic for Vitamin C degradation proved the matrix tolerance of the introduced method.